I'm sure most of us have heard of zip bombs and similar decompression bomb tricks, where a maliciously crafted input creates a massively disproportionate output. We even had a question on here to do that to a compiler at one point.

Well, it occurs to me that Markdown is a compression format of sorts, replacing bulky HTML tags with "compressed" MD tokens. Therefore, might it be possible to build a compression bomb in Markdown?

Challenge rules:

The submission should be a piece of markdown text, between 50 and 256 characters in length. (Imposing a minimum to head off some smart-aleck posting a 3-character response or similar.)
The submission will be processed by StackExchange's Markdown processor as implemented in this site.
Your score will be the ratio of character count in the resulting HTML to the character count of your Markdown text.
Highest score wins.

Mason Wheeler

Posted 2018-09-19T19:15:36.600

Reputation: 1 254

The Formatting Sandbox may come in handy for people to test before they post an answer.

– Engineer Toast – 2018-09-19T20:36:23.903

7We might need a standard interpreter / viewer / checker system. People are getting different byte counts for the same code because some tags are / are not showing up. – Engineer Toast – 2018-09-19T21:06:51.553

3This is going to devolve into mathjax/latex actual busy beaver code – isaacg – 2018-09-20T02:14:29.837

@isaacg: I'll be impressed if you can come up with something that's worse than linear after trimming indentation. – Joshua – 2018-09-20T03:15:23.200

@Joshua See this answer: https://codegolf.stackexchange.com/a/172523/20080

– isaacg – 2018-09-20T03:16:36.783

1Should Mathjax actually be allowed? It's not Markdown. – curiousdannii – 2018-09-20T07:00:14.380

6Should we count the rendered HTML or the source HTML? Language highlighting and MathJax are done client-side, not server-side. – user202729 – 2018-09-20T07:23:43.020

5Warning: Testing some large answers to this challenge may exhaust your RAM. – user202729 – 2018-09-20T10:19:50.817

@curiousdannii I did say "the markdown interpreter as implemented in this site." Some SE sites have MathJax support, but I think this isn't one of them, and I've noticed that none of the MathJax examples actually show the rendered output. – Mason Wheeler – 2018-09-20T13:08:53.273

@MasonWheeler This list says this site does support Mathjax. But it still doesn't make sense to me for mathjax to be considered markdown just because it can be combined with it. Edit: now I see below that you also don't think it counts. So cool :)

– curiousdannii – 2018-09-20T13:11:37.720

1The "rendered or source" issue and whether MathJax is allowed really needs to be clarified. You can't just say "ok this is probably invalid but nice". – user202729 – 2018-09-21T10:40:15.573

1Voting to close as unclear. Unfortunately, StackExchange markup rendering is not a consistent interpreter, as it will change over time, and there will be no way to verify old answers once it does, because you cannot link to an old "interpreter". – mbomb007 – 2018-09-21T13:21:14.490

@Timtech It's weird that OP accepts the highest voted instead of the highest score answer, but "score" != "votes tally". Not a pop-con. – user202729 – 2018-09-22T02:08:36.373

1@MasonWheeler You should fix this some way soon or it will be closed. It has 4 close votes already. – user202729 – 2018-09-22T02:11:09.323

@user202729 My bad, looking back I don't know how I got the impression that this was a popularity contest. – Timtech – 2018-09-25T01:37:55.293

Answers

106

Blockquotes, 137,469/256 = 536.99

6,908 characters, 511 new lines, 130,050 spaces

Markdown sure handles nested block-quotes oddly. Each > character gets turned into <blockquote></blockquote> so a solid 1 to 25 ratio. But wait! When rendering the HTML it also adds two spaces per nesting! Having this try to render causes my browser some grief, and I will keep it in the code-cage for now. Feel free to unlock it yourself!

The code input consists of 255 > followed by & as the last character doesn't transform, but it does get escaped. Thanks BWO ! as the last character which gives the last blockquote the spoiler class with an empty p tag inside. Thanks bta, 11 extra characters

Input: >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>!

Output HTML:

...
  <blockquote>
    <blockquote class="spoiler">
      <p></p>
    </blockquote>
  </blockquote>
...

Here is what it looks like in the editor view!

Plotting the results as the number of > increase as suggested by LambdaBeta:

Sven Writes Code

Posted 2018-09-19T19:15:36.600

Reputation: 974

Try plotting the results as you increase the '>' count. I wonder if the renderer will also add the formatting spaces... – LambdaBeta – 2018-09-19T21:07:35.587

2The funny thing here is, that the blockquotes nicely overflow the article column at least in the editing preview. – ilkkachu – 2018-09-19T22:27:05.380

4If you add ! before the ampersand, then the last level of blockquote will get class="spoiler" added to it. Add it to any other level and it shortens the output, though. – bta – 2018-09-20T00:18:13.717

removing one greater than sign loses 1k characters! :0 – Sven Writes Code – 2018-09-20T00:38:48.573

1I'm so ashamed I didn't think of this – slebetman – 2018-09-20T04:52:29.593

@SvenWritesCode - True. You can also replace the trailing & with ! to get the same effect. – bta – 2018-09-20T23:26:31.717

1Now this is "arrow code" if I've ever seen it. – ZeroKnight – 2018-09-21T06:42:21.423

3Nice. This is quadratic growth because the j-th quote adds O(j) new characters, so we get big-O of 1+2+...+n = O(n^2). You can see this from the picture where the triangle's height is the number of quotes n and its width is O(n), so its area is O(n^2). The other non-Mathjax answers seem to be only linear growth (the billion-laughts MathJax one is exponential). – usul – 2018-09-21T14:37:26.660

1@usul The shorthand links answer is also quadratic growth; the length of the URL is multiplied by the number of references to it. – Misha Lavrov – 2018-09-21T15:02:49.233

MathJax, 529\$\,\$252\$\,\$640_ish / 256 ≈ 2\$\,\$067\$\,\$393

A good old thousand-laughs-style code

$$\def\a{}\def\b{\a\a\a\a\a\a\a\a\a\a\a\a\a}\def\c{\b\b\b\b\b\b\b\b\b\b\b}\def\d{\c\c\c\c\c\c\c\c}\d\d\d\d\d\d\d\d$$

multiplies the gross inefficiency of representing exotic characters in MathJax by a considerable factor.

The StackExchange MathJax configuration limitation of 10\$\,\$000 macro expansions is being honored, while the limitations of the client’s browser, which are highly likely to cause problems expanding the macros, are not. (My browser is uncooperative as well, so the figure is an estimate.)

Roman Odaisky

Posted 2018-09-19T19:15:36.600

Reputation: 511

For anyone else wondering: https://en.wikipedia.org/wiki/Billion_laughs_attack

– JollyJoker – 2018-09-20T10:00:58.387

– user202729 – 2018-09-20T10:22:34.860

@user202729 my code causes something like 8865 macro expansions, out of 10000 permitted by MathJax as configured on StackExchange. If not for that restriction, less tildes and more nesting levels would produce way more output. – Roman Odaisky – 2018-09-20T12:06:54.437

2This is a cool find, but it's not Markdown and MathJax is not supported on this site, so it's kind of outside the stated parameters of the rules. – Mason Wheeler – 2018-09-20T13:10:09.530

$are^{you^{sure}}$ it’s not supported? The page titled “Markdown Editing Help” at https://codegolf.stackexchange.com/editing-help explicitly mentions LaTeX.

– Roman Odaisky – 2018-09-20T13:27:22.870

It would be a nice exercise to see what ratio of definition lengths would yield the longest result. How many ~ in \a, how many \a in \b, and so on (and whether to stop at \d, or keep going). – Arthur – 2018-09-20T15:15:37.153

@Arthur do you think the numbers chosen are random? :−) – Roman Odaisky – 2018-09-20T15:19:37.880

1@RomanOdaisky Not at all. You've probably done the calculation yourself, and reached this conclusion. I'm just saying, as a math teacher and enthusiast, that it seems like it would be a cool exercise. – Arthur – 2018-09-20T15:30:46.617

1Hmm. It's easy to make much larger expansion in (La)TeX proper, but all fun seems to be disallowed in MathJax: count registers, conditionals, \expandafter, even \edef. – Emil Jeřábek 3.0 – 2018-09-20T15:37:26.777

@RomanOdaisky if you embed a simplified version of the code in your post to demonstrate that the theory works in the specified environment (i.e. "here"), I suspect the debate of "whether or not it's supported" will be a bit easier to resolve. – Kamil Drakari – 2018-09-20T17:13:55.520

6@KamilDrakari Your wish is my command $\def\a{}\def\b{\a\a}\def\c{\b\b}\def\d{\c\c}\d\d$ – Roman Odaisky – 2018-09-20T17:17:10.570

Shorthand links: 68,960 / 256 = 269.375

ASCII only: 10,114 / 256 = 39.508

[][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1][][1]
[1]:ftp://^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Output is a sequence of elements that each look like:

<a href="ftp://%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E%5E" rel="nofollow noreferrer"></a>

After the fixed overhead for creating the URL reference, each 5-character link expands into 42+strlen(url) characters output. Craft the URL to have the maximum number of characters that need escaping, and this grows to 47+3*strlen(url) characters per link. A little experimentation showed that the optimal output involved 26 links, with 114 carets per link.

Update: If you interpret the "256 character" limit to include Unicode characters, you can squeeze out more chaos. Replacing the carets with the Unicode bathtub character (, codepoint U+1F6C1) results in 47+18*strlen(url) output characters per input character for a total of ~~54,574~~ 68,960 (thanks to jimmy23013's even-shorter link notation).

Unicode input:

[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1]
[1]:ftp://

Output is a series of:

<a href="ftp://%EF%BF%BD%EF%BF%BD...per character...%EF%BF%BD%EF%BF%BD" rel="nofollow noreferrer">1</a>,

bta

Posted 2018-09-19T19:15:36.600

Reputation: 361

Welcome to PPCG! This is a very clever answer! – Mego – 2018-09-20T01:55:53.503

You can use [1],[1],[1]... for the links. 2. " has more characters than %5E in the non-Unicode version.

< – jimmy23013 – 2018-09-21T14:41:00.487

15888/50 = 317.76: Abuse of MathJaX

This is the code:

$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$

This is what it looks like:

$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$$$&$$

The resulting HTML is:

<p><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-618-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3081" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3082"><span id="MathJax-Span-3083" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3084"><span class="mtext" id="MathJax-Span-3085" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-618">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-619-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3086" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3087"><span id="MathJax-Span-3088" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3089"><span class="mtext" id="MathJax-Span-3090" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-619">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-620-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3091" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3092"><span id="MathJax-Span-3093" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3094"><span class="mtext" id="MathJax-Span-3095" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-620">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-621-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3096" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3097"><span id="MathJax-Span-3098" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3099"><span class="mtext" id="MathJax-Span-3100" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-621">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-622-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3101" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3102"><span id="MathJax-Span-3103" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3104"><span class="mtext" id="MathJax-Span-3105" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-622">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-623-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3106" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3107"><span id="MathJax-Span-3108" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3109"><span class="mtext" id="MathJax-Span-3110" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-623">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-624-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3111" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3112"><span id="MathJax-Span-3113" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3114"><span class="mtext" id="MathJax-Span-3115" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-624">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-625-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3116" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3117"><span id="MathJax-Span-3118" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3119"><span class="mtext" id="MathJax-Span-3120" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-625">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-626-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3121" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3122"><span id="MathJax-Span-3123" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3124"><span class="mtext" id="MathJax-Span-3125" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-626">&</script><span class="MathJax_Preview" style="display: none;"></span><div class="MathJax_Display" style="text-align: center;"><span class="MathJax" id="MathJax-Element-627-Frame" tabindex="0" style="text-align: center; position: relative;" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; display=&quot;block&quot;><merror><mtext>Misplaced &amp;amp;</mtext></merror></math>" role="presentation"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-3126" style="width: 5.447em; display: inline-block;"><span style="display: inline-block; position: relative; width: 4.503em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(1.114em, 1004.5em, 2.614em, -999.997em); top: -2.164em; left: 0em;"><span class="mrow" id="MathJax-Span-3127"><span id="MathJax-Span-3128" style="display: inline-block;"><span class="merror" id="null"><span class="mrow" id="MathJax-Span-3129"><span class="mtext" id="MathJax-Span-3130" style=""><span style="font-size: 83%;">Misplaced &amp;</span></span></span></span></span></span><span style="display: inline-block; width: 0px; height: 2.169em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.397em; border-left: 0px solid; width: 0px; height: 1.537em;"></span></span></nobr><span class="MJX_Assistive_MathML MJX_Assistive_MathML_Block" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><merror><mtext>Misplaced &amp;</mtext></merror></math></span></span></div><script type="math/tex; mode=display" id="MathJax-Element-627">&</script></p>

Don't forget your MathJax folks.

Caveat: The MathJaX only shows the error during editing, so you have to view it in the editor. This is still a markdown implementation on this site, so should be valid. Once posted the Misplaced & warnings turn into normal &'s.

LambdaBeta

Posted 2018-09-19T19:15:36.600

Reputation: 2 499

Syntax highlighting, 6376 6464/256 ≈ 25.25

^{+0.34375 thanks to Ismael Miguel (using a tab instead of 4 spaces)!}

This uses the shortest (unfortunately spaces seem to matter) annotation to get syntax-highlighting lang-c, opens a code block and fills it with & and 0:

<!-- language: lang-c -->

    &0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0

We start with & because it expands to & and use 0 next, alternating these constantly creates new  elements with a class attribute. Unfortunately we can't use only & or &<&<... since they stay in the same pun-<div>

It produces:

<pre class="lang-c prettyprint prettyprinted" style=""><code><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span><span class="pun">&amp;</span><span class="lit">0</span></code></pre></div>

And rendered by your browser it results in:

&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0&0

ბიმო

Posted 2018-09-19T19:15:36.600

Reputation: 15 345

If you look at the source code for this page, the HTML is just <pre class="lang-c prettyprint-override"><code>&0&0& ... 0&0&0& </code></pre> where ... is more of the same. The span tags aren't there at all. That's a score of 739/256 = 2.887 – Engineer Toast – 2018-09-19T20:56:57.187

@EngineerToast: What browser? I'm using Firefox 62 and they show up, I noticed with another answer that I get another score, so I guess this depends on the browser.. – ბიმო – 2018-09-19T21:04:11.203

2Well... That's going to be a problem. I'll ask OP to standardize. – Engineer Toast – 2018-09-19T21:05:36.850

@EngineerToast That's caused by this.

– user202729 – 2018-09-20T10:04:49.737

1Instead of 4 spaces, use a single tab. It works too! – Ismael Miguel – 2018-09-21T14:59:24.040

190/50 = 3.8: Italics

As it turns out, your 3-character worry is true. *q* generates q giving a ratio of 10/3. Two carriage returns give ...\n\n (the two carriage returns aren't necessary, but do appear to be produced) and a resulting ratio of 9/2. Total ratio, 19/5.

*q*

*q*

*q*

*q*

*q*

*q*

*q*

*q*

*q*

*q*

Resulting html:

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

<p><em>q</em></p>

In action:

Draco18s no longer trusts SE

Posted 2018-09-19T19:15:36.600

Reputation: 3 053

1Using > q to use <blockquote> instead of  is better. (note: you do it to every other line, otherwise its just one tag) – LambdaBeta – 2018-09-19T20:32:52.407

@LambdaBeta I didn't even think about Blockquote. Yeah, that one exploded.

– Draco18s no longer trusts SE – 2018-09-19T21:01:23.213

222/53 = <4.2: Nasty escapes in an image inclusion.

> ![&](https://&)

![&](https://&)
> ![&](https://&)

Results in:

Resulting HTML should be approximately:

<blockquote>
  <p><img src="https://&amp;" alt="&amp;" title=""></p>
</blockquote>

<p><img src="https://&amp;" alt="&amp;" title=""></p>

<blockquote>
  <p><img src="https://&amp;" alt="&amp;" title=""></p>
</blockquote>

This abuses image inclusion and having to escape things.

It used to be much better, but apparently SE's markdown is sufficiently non-standard to ruin it.

My previous submission (which wasn't how SE rendered it) was:

428/50 = 8.56: Nasty escapes in an image inclusion.

![&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&](&)

Resulting HTML should be approximately:

<p><img src="&amp;" alt="&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;&amp;amp;"></p>

This abuses the fact that most markdown editors will replace the ampersands in the alt text with doubly-escaped ampersands in order for it to show up correctly. Meanwhile a single ampersand is tossed into the src section so that the parser will actually see it as an image.

LambdaBeta

Posted 2018-09-19T19:15:36.600

Reputation: 2 499

Would ε be translated to ε or ε? – Jonathan Frech – 2018-09-19T20:19:12.043

I don't know. As far as I can tell it doesn't actually work - debugging it a bit now. I used & because in theory for alt-text to show up correctly it has to be escaped twice (&). This works in most markdowns, but doesn't seem to produce any output at all in SE... – LambdaBeta – 2018-09-19T20:20:19.667

Couldn't you compress this with [1]:https://& on a line, and then use ![&][1] more times? – wizzwizz4 – 2018-09-20T20:35:48.283

Does it really have to be https? http would give you less unexpanded characters. Or ftp if that works. – user253751 – 2018-09-24T01:45:19.690

MathJax: 13,579 / 52 = 261.13

\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$

Just creates a bunch of empty in-line MathJax:

\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$\$

HTML Code (can inspect on the empty space above):

<p><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1064-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2127" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2128"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1064"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1065-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2129" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2130"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1065"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1066-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2131" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2132"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1066"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1067-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2133" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2134"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1067"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1068-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2135" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2136"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1068"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1069-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2137" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2138"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1069"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1070-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2139" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2140"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1070"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1071-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2141" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2142"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1071"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1072-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2143" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2144"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1072"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1073-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2145" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2146"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1073"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1074-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2147" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2148"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1074"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1075-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2149" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2150"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1075"></script><span class="MathJax_Preview" style="display: none;"></span><span class="MathJax" id="MathJax-Element-1076-Frame" tabindex="0" data-mathml="<math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot; />" role="presentation" style="position: relative;"><nobr aria-hidden="true"><span class="math" id="MathJax-Span-2151" style="width: 0em; display: inline-block;"><span style="display: inline-block; position: relative; width: 0em; height: 0px; font-size: 120%;"><span style="position: absolute; clip: rect(3.785em, 1000em, 4.17em, -999.997em); top: -3.971em; left: 0em;"><span class="mrow" id="MathJax-Span-2152"></span><span style="display: inline-block; width: 0px; height: 3.978em;"></span></span></span><span style="display: inline-block; overflow: hidden; vertical-align: -0.073em; border-left: 0px solid; width: 0px; height: 0.158em;"></span></span></nobr><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"></math></span></span><script type="math/tex" id="MathJax-Element-1076"></script></p>

Stephen

Posted 2018-09-19T19:15:36.600

Reputation: 12 293

You can get more with errors. Take a look at my answer. – LambdaBeta – 2018-09-19T21:00:48.367

4830 / 256 = 18.87

[1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1<p>1](http://localhost:8080/welcome-to-my-fantastic-amazing-homepage-and-why-not-share-it-to-your-facebook-right-now.html)

An idea based on HTML autocorrect. Not quite high score though.

tsh

Posted 2018-09-19T19:15:36.600

Reputation: 13 072

421 / 56 = 7.518

>&

&
>&

&
>&

&
>&

&
>&

&
>&

&
>&

Which produces the following HTML on SE:

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

<p>&amp;</p>

<blockquote>
  <p>&amp;</p>
</blockquote>

... and the following output:

&

Engineer Toast

Posted 2018-09-19T19:15:36.600

Reputation: 5 769

11190 / 255 = ~43.88

I was inspired by this top answer, but am too dumb to beat it and reached the max character count so, I guess I'll have to be satisfied with what I have ¯\_(ツ)_/¯. There's actually two spaces after the last blockquote, but the formatting does not show it.

> - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - > - >

HTML:

<blockquote>
  <ul>
  <li><blockquote>
    <ul><li><blockquote>
      <ul><li><blockquote>
        <ul><li><blockquote>
          <ul><li><blockquote>
            <ul><li><blockquote>
              <ul><li><blockquote>
                <ul><li><blockquote>
                  <ul><li><blockquote>
                    <ul><li><blockquote>
                      <ul><li><blockquote>
                        <ul><li><blockquote>
                          <ul><li><blockquote>
                            <ul><li><blockquote>
                              <ul><li><blockquote>
                                <ul><li><blockquote>
                                  <ul><li><blockquote>
                                    <ul><li><blockquote>
                                      <ul><li><blockquote>
                                        <ul><li><blockquote>
                                          <ul><li><blockquote>
                                            <ul><li><blockquote>
                                              <ul><li><blockquote>
                                                <ul><li><blockquote>
                                                  <ul><li><blockquote>
                                                    <ul><li><blockquote>
                                                      <ul><li><blockquote>
                                                        <ul><li><blockquote>
                                                          <ul><li><blockquote>
                                                            <ul><li><blockquote>
                                                              <ul><li><blockquote>
                                                                <ul><li><blockquote>
                                                                  <ul><li><blockquote>
                                                                    <ul><li><blockquote>
                                                                      <ul><li><blockquote>
                                                                        <ul><li><blockquote>
                                                                          <ul><li><blockquote>
                                                                            <ul><li><blockquote>
                                                                              <ul><li><blockquote>
                                                                                <ul><li><blockquote>
                                                                                  <ul><li><blockquote>
                                                                                    <ul><li><blockquote>
                                                                                      <ul><li><blockquote>
                                                                                        <ul><li><blockquote>
                                                                                          <ul><li><blockquote>
                                                                                            <ul><li><blockquote>
                                                                                              <ul><li><blockquote>
                                                                                                <ul><li><blockquote>
                                                                                                  <ul><li><blockquote>
                                                                                                    <ul><li><blockquote>
                                                                                                      <ul><li><blockquote>
                                                                                                        <ul><li><blockquote>
                                                                                                          <ul><li><blockquote>
                                                                                                            <ul><li><blockquote>
                                                                                                              <ul><li><blockquote>
                                                                                                                <ul><li><blockquote>
                                                                                                                  <ul><li><blockquote>
                                                                                                                    <ul><li><blockquote>
                                                                                                                      <ul><li><blockquote>
                                                                                                                        <ul><li><blockquote>
                                                                                                                          <ul><li><blockquote>
                                                                                                                            <ul><li><blockquote>
                                                                                                                              <ul><li><blockquote>

                                                                                                                              </blockquote></li></ul>
                                                                                                                            </blockquote></li></ul>
                                                                                                                          </blockquote></li></ul>
                                                                                                                        </blockquote></li></ul>
                                                                                                                      </blockquote></li></ul>
                                                                                                                    </blockquote></li></ul>
                                                                                                                  </blockquote></li></ul>
                                                                                                                </blockquote></li></ul>
                                                                                                              </blockquote></li></ul>
                                                                                                            </blockquote></li></ul>
                                                                                                          </blockquote></li></ul>
                                                                                                        </blockquote></li></ul>
                                                                                                      </blockquote></li></ul>
                                                                                                    </blockquote></li></ul>
                                                                                                  </blockquote></li></ul>
                                                                                                </blockquote></li></ul>
                                                                                              </blockquote></li></ul>
                                                                                            </blockquote></li></ul>
                                                                                          </blockquote></li></ul>
                                                                                        </blockquote></li></ul>
                                                                                      </blockquote></li></ul>
                                                                                    </blockquote></li></ul>
                                                                                  </blockquote></li></ul>
                                                                                </blockquote></li></ul>
                                                                              </blockquote></li></ul>
                                                                            </blockquote></li></ul>
                                                                          </blockquote></li></ul>
                                                                        </blockquote></li></ul>
                                                                      </blockquote></li></ul>
                                                                    </blockquote></li></ul>
                                                                  </blockquote></li></ul>
                                                                </blockquote></li></ul>
                                                              </blockquote></li></ul>
                                                            </blockquote></li></ul>
                                                          </blockquote></li></ul>
                                                        </blockquote></li></ul>
                                                      </blockquote></li></ul>
                                                    </blockquote></li></ul>
                                                  </blockquote></li></ul>
                                                </blockquote></li></ul>
                                              </blockquote></li></ul>
                                            </blockquote></li></ul>
                                          </blockquote></li></ul>
                                        </blockquote></li></ul>
                                      </blockquote></li></ul>
                                    </blockquote></li></ul>
                                  </blockquote></li></ul>
                                </blockquote></li></ul>
                              </blockquote></li></ul>
                            </blockquote></li></ul>
                          </blockquote></li></ul>
                        </blockquote></li></ul>
                      </blockquote></li></ul>
                    </blockquote></li></ul>
                  </blockquote></li></ul>
                </blockquote></li></ul>
              </blockquote></li></ul>
            </blockquote></li></ul>
          </blockquote></li></ul>
        </blockquote></li></ul>
      </blockquote></li></ul>
    </blockquote></li></ul>
  </blockquote></li>
  </ul>
</blockquote>

an earwig

Posted 2018-09-19T19:15:36.600

Reputation: 141

2the code itself looks like a blockquote – qwr – 2018-09-23T23:45:29.367

Build a Markdown bomb

Challenge rules:

Answers

Blockquotes, 137,469/256 = 536.99

MathJax, 529\$\,\$252\$\,\$640ish / 256 ≈ 2\$\,\$067\$\,\$393

Shorthand links: 68,960 / 256 = 269.375

15888/50 = 317.76: Abuse of MathJaX

Syntax highlighting, 6376 6464/256 ≈ 25.25

190/50 = 3.8: Italics

222/53 = <4.2: Nasty escapes in an image inclusion.

428/50 = 8.56: Nasty escapes in an image inclusion.

MathJax: 13,579 / 52 = 261.13

4830 / 256 = 18.87

421 / 56 = 7.518

11190 / 255 = ~43.88

MathJax, 529\$\,\$252\$\,\$640_ish / 256 ≈ 2\$\,\$067\$\,\$393