Print an alphabet wave

Question

You are to print this exact text:

ABABABABABABABABABABABABAB
BCBCBCBCBCBCBCBCBCBCBCBCBC
CDCDCDCDCDCDCDCDCDCDCDCDCD
DEDEDEDEDEDEDEDEDEDEDEDEDE
EFEFEFEFEFEFEFEFEFEFEFEFEF
FGFGFGFGFGFGFGFGFGFGFGFGFG
GHGHGHGHGHGHGHGHGHGHGHGHGH
HIHIHIHIHIHIHIHIHIHIHIHIHI
IJIJIJIJIJIJIJIJIJIJIJIJIJ
JKJKJKJKJKJKJKJKJKJKJKJKJK
KLKLKLKLKLKLKLKLKLKLKLKLKL
LMLMLMLMLMLMLMLMLMLMLMLMLM
MNMNMNMNMNMNMNMNMNMNMNMNMN
NONONONONONONONONONONONONO
OPOPOPOPOPOPOPOPOPOPOPOPOP
PQPQPQPQPQPQPQPQPQPQPQPQPQ
QRQRQRQRQRQRQRQRQRQRQRQRQR
RSRSRSRSRSRSRSRSRSRSRSRSRS
STSTSTSTSTSTSTSTSTSTSTSTST
TUTUTUTUTUTUTUTUTUTUTUTUTU
UVUVUVUVUVUVUVUVUVUVUVUVUV
VWVWVWVWVWVWVWVWVWVWVWVWVW
WXWXWXWXWXWXWXWXWXWXWXWXWX
XYXYXYXYXYXYXYXYXYXYXYXYXY
YZYZYZYZYZYZYZYZYZYZYZYZYZ
ZAZAZAZAZAZAZAZAZAZAZAZAZA

Specs

• You can print all lowercase instead of all uppercase. However, case must be consistent throughout the output.
• You may print one extra trailing linefeed.

Scoring

Since this is an alphabet wave that fluctuates to a small extent, your code should also be small in terms of byte-count. In fact, the smallest code in terms of byte-count wins.

Answer 1

C, 60 bytes

main(i){for(;i<703;)putchar(i++%27?65+(i/27+i%27%2)%26:10);}

Answer 2

Brainfuck, 104 bytes

>+[+[<]>>+<+]><<+++++[>+++++>>++<<<-]>[-<+++++++++++++[->>.+.-<<]>>>.<+<]<----[>+<----]>++>>+++[-<.<.>>]

Answer 3

Convex, 10 bytes

U_(+]D*zN*

Try it online!

U               Predefined Variable: "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 _(+            Push a copy with the 'A at the end.
    ]           Add both strings to an array.
     D*         Repeat array 13 times. D defaults to 13.
       z        Transpose.
        N*      Join by newlines. N defaults to "\n"

Answer 4

Pyth, 11 10 bytes

jC*13.<BG1

Try it here.

        G   the alphabet
       B    bifurcate over
     .<  1  left shift by 1
  *13       repeat 13 times
 C          transpose
j           join on newlines

Answer 5

Ruby, 42 39 38 37 bytes

-3 bytes thanks to @user81655
-1 byte thanks to @manatwork
-1 byte thanks to @NotthatCharles

?A.upto(?Z){|a|puts (a+a.next[0])*13}

See it on repl.it: https://repl.it/CmOJ

Answer 6

Vim, 85 83 bytes

:h<_<cr><cr><cr>YZZP:s/./\0\r/g<cr><c+v>ggy25Pqqlxj:let @a='xkPjj'<cr>25@akia<esc>25klq11@qh<ctrl+v>25jylpl<c+v>25jdGdd

I know this can be golfed more, but my head hurts so I gotta stop for now.

<cr> is the enter key, <c+v> is ctrl+v, and <esc> is the escape key. Those were all counted as one byte.

I recorded a gif of this, but it got screwed up. The video is fine though: http://recordit.co/ldLKvho9Gi

Answer 7

Cheddar, 48 bytes

print(65|>90).map(l->@"[l,l>89?65:l+1]*13).vfuse

Cheddar is good with strings :D

Try it online!

Explanation

print
  (65|>90)            // Range from 65 (A) to 90 (Z)
  .map(l->            // Map through range
    @"                // Convert following array of char codes to string
      [l,             // The character 
       l>89?65:l+1]   // See below for explanation
      *13             // Repeat 13 times
  ).vfuse             // Vertically fuse

What does l>89?65:l+1 do? Well 89 is the char code for Y. Basically, l>89 is checking if the letter is Z, that means we should be returning A. If l>89 is false. I'll return l+1, the next char

Answer 8

Haskell, 60 58 bytes

mapM putStrLn[[0..12]>>[a,b]|a:b:_<-scanr(:)"A"['A'..'Z']]

Starting with "A" scanr(:) builds the a list from the chars of ['A'..'Z'] from the right. (-> ["ABCDE...A", "BCDEF..A", ..., "XYZA", "YZA", "ZA", "A"]). (a:b:_) matches the first two chars of each sublists (with at least two chars) and makes 13 copies of it.

Answer 9

Jelly, 10 bytes

26ḶḂØAṙZj⁷

Try it online!

How it works

26ḶḂØAṙZj⁷  Main link. No arguments.

26Ḷ         Yield [0, ..., 25].
   Ḃ        Bit; compute the parity of each intger.
    ØAṙ     Rotate the alphabet by these amounts.
       Z    Zip; transpose rows and columns.
        j⁷  Join, separating by linefeeds.

Answer 10

PowerShell, 49 43 bytes

TimmyD's remix:

65..89|%{-join[char[]]($_,++$_)*13};"ZA"*13

was, 49 bytes:

0..25|%{(""+[char]($_+++65)+[char]($_%26+65))*13}

Answer 11

Python 2, 70 68 54 bytes

List based solution:

L=map(chr,range(65,91))
for i in range(-26,0):print(L[i]+L[i+1])*13

But why create a list? Thanks LeakyNun:

for i in range(26):print(chr(i+65)+chr(-~i%26+65))*13

Answer 12

R, 72 67 60 56 bytes

write(matrix(LETTERS[c(1:26,2:26,1)],26,26,T),"",26,,"")

Thanks to @Giuseppe for the extra 4 bytes off!

Old rep-based solution at 60 bytes:

for(i in 1:26)cat(rep(LETTERS[c(i,i%%26+1)],13),"\n",sep="")

See here on an online interpreter. Thanks to @user5957401 for the extra 7 bytes off!

Old matrix-based solution at 72 bytes:

for(i in 1:26)cat(matrix(LETTERS[c(1:26,2:26,1)],26,26)[i,],"\n",sep="")

See here on an online interpreter.

Answer 13

Perl, 26 bytes

Solution from @Dom Hastings. (12 bytes shorter than mine!)
-1 byte thanks to @Ton Hospel

say+($_++,chop)x13for A..Z

Run with -M5.010 or -E :

perl -E 'say+($_++,chop)x13for A..Z'

Answer 14

MATL, 13 bytes

1Y2tn:!to~!+)

Try it online!

1Y2    % Predefined string literal: 'AB···Z'
tn:    % Duplicate, number of elements, range: gives [1, 2, ···, 26]
!      % Transpose into a column vector
to~!   % Duplicate and transform into [0, 1, 0, 1, ···, 1] using modulo 2
+      % Addition with broadcast. Gives 2D numeric array
)      % Index (modularly) into string. Implicitly display.

Answer 15

Jellyfish, 26 bytes

P
+'A
~
| S
+$ r2
 ,'
r'

Note the trailing unprintable characters on the last two lines. Try it online!

Explanation

This is basically an arithmetic manipulation approach: make a 26×26 grid with alternating 0-1 pattern, add the index of each row to every element of the row, reduce mod 26, and add the ASCII value of A. Characters in Jellyfish are just numbers with a special flag, and all arithmetic works on them as expected.

From bottom to top:

• The 's are character literals; they are followed by unprintables with ASCII code 26, and stand for those characters.
• The lower r computes the character range from 0 to 25.
• The , forms a pair from the two unprintable chars.
• The higher r is given argument 2, and forms the range [0 1].
• The $ takes that range, and reshapes it into the shape given by its other argument, which is the pair of unprintables. This gives a 26×26 matrix of alternating rows 0 1 0 1 0 1 ...
• The lower + adds the char range 0-25 to this matrix. The addition distributes on the rows, so row i is incremented by i. It's also converted to a char matrix, since the south argument consists of chars.
• The ~| is modulus with flipped arguments: the south argument (the above char matrix) is reduced modulo the east argument (the S turns the argument-seeking process south, so this is the unprintable literal 26).
• The higher + adds the literal A to every coordinate of the resulting matrix.
• The P prints the result in matrix format, that is, each row on its own line without quotes.

Answer 16

T-SQL 133 Bytes (Golfed by : @t-clausen.dk)

SELECT REPLICATE(Char(number+65)+IIF(number=25,'A',Char(number+66)),13)FROM spt_values WHERE number<26and'P'=TYPE

T-SQL , 151 Bytes

Using CTE to generate sequence of number

;WITH n(a,v) AS(SELECT CHAR(65)+CHAR(66), 66 UNION ALL SELECT CHAR(v)+CHAR(v+1), v+1 FROM n WHERE v < 91)SELECT REPLICATE(REPLACE(a,'[','A'),13) FROM n

T-SQL, 155 Bytes

SELECT REPLICATE(Char(number+65)+ CASE WHEN number=25 THEN 'A' ELSE Char(number+66) END, 13) FROM master.dbo.spt_values  WHERE name IS NULL AND number < 26

Answer 17

Vim, 31 bytes

:h<_↵↵↵YZZPJra0qqy2l13Plr↵25@qD

Where ↵ is the Return key.

Answer 18

Julia, 46 bytes

[println("$c$(c+1-26(c>89))"^13)for c='A':'Z']

Try it online!

Answer 19

Pyth, 10 bytes

jCm.<G~!ZG

Demonstration

Explanation:

jCm.<G~!ZG
  m      G    Map over G, predefined to the lowercase alphabet.
              This will give 26 columns.
   .<G        Left shift (cyclically) G by
        Z     Z elements. Z is initialized to 0.
      ~!      After using its value, logical not Z. (0 -> 1, 1 -> 0)
 C            Transpose
j             Join on newlines

Answer 20

Brainfuck, 88 86 bytes

++[[+>]<+<++]+>-[[->+>+<<]>>-]++++++++[<[++++++++<+<]>[>]<-]<<++<[>+++[->.<<.>]<<++.<]

Requires an interpreter with 8-bit cells and a tape not bounded on the left. Try it online!

Answer 21

Lua, 80 65 Bytes.

s = string c = s.char for i=1,26 do print(s.rep(c(64+i)..c((65+(i%26))),13)) end

With help from Leaky Nun

c=("").char for i=1,26 do print((c(64+i)..c(65+i%26)):rep(13))end

Lua is a pretty inefficent language in regards to handling of strings and such, so this is the best I can narrow it down.

Answer 22

Brachylog, 30 24 20 bytes

@Ab:"a"c:@Arz:{:12jc:@Nc.}a:wa
@Ab:"a"c:@Arze:12jcw@Nw\
@A$(:@Arze:12jcw@Nw\

Try it online!

Answer 23

05AB1E, 12 bytes

ADÀ)øvyJ5Ø×,

Explanation

AD            # push 2 copies of the alphabet
  À           # rotate the 2nd one left by 1
   )ø         # add to list and zip
     v        # for each
      yJ      # join the pair
        5Ø×   # repeat it 13 times
           ,  # print with newline

Try it online

Answer 24

TSQL, 111 bytes

DECLARE @o varchar(702)='',@ int=1WHILE @<702SELECT @o+=CHAR(IIF(@%27=0,10,65+(@/27+1-@%27%2)%26)),@+=1PRINT @o

Fiddle

Answer 25

Mathematica, 82 75 67 66 bytes

Print@FromCharacterCode@PadLeft[{},26,{i-1,i}~Mod~26+65]~Do~{i,26}

Technically shorter, although it prints in lowercase instead of uppercase:

Mathematica, 64 bytes

Print[""<>FromLetterNumber@Table[{i-1,i}~Mod~26+1,13]]~Do~{i,26}

Answer 26

Common Lisp, SBCL, 86 bytes

(dotimes(i 26)(format t"~13@{~a~:*~}~%"(subseq"ABCDEFGHIJKLMNOPQRSTUVWXYZA"i(+ i 2))))

Explanation

(dotimes(i 26);loop from i=0 to i=25
(format t"~13@{~a~:*~}~%"(subseq"ABCDEFGHIJKLMNOPQRSTUVWXYZA"i(+ i 2))))
;print 13 times pairs of "AB", "BC", ... , "ZA"

Answer 27

c64 basic v2, 95 93 85 83 77 bytes

0fOy=65to90:l$="":a$=cH(y)+cH(y+1+(y=90)*26)
1fOx=0to12:l$=l$+a$:nE:?l$:nE

Screenshot:

Trial instructions are in my previous answer.

Answer 28

SOGL V0.12, 8 bytes

Z«Z¹'⁰∙I

Try it Here!

Explanation:

Z         push the uppercase alphabet
 «        put its first letter at the end
  Z       push the alphabet once again
   ¹      wrap in array: ["BCDEFGHIJKLMNOPQRSTUVWXYZA", "ABCDEFGHIJKLMNOPQRSTUVWXYZ"]
    '⁰∙   multiply vertically 13 times
       I  rotate clockwise

Answer 29

Bash, 64 bytes

f()(tr A-Z B-ZA|tee >(((i++<25))&&f);echo)
printf ZA%.s {a..m}|f

Credit to seshoumara's sed answer for the idea of translating A-Z to B-ZA.

Try it online!

Answer 30

JavaScript (ES6), 88 83 bytes

_=>[..."ABCDEFGHIJKLMNOPQRSTUVWXYZ"].map((c,i,a)=>(c+a[-~i%26]).repeat(13)).join`\n`

Where \n represents the literal newline character. Writing the alphabet out saved me three bytes today, but @LeakyNun saved me another five bytes.

Answer 31

J, 20 19 bytes

1 byte thanks to miles.

u:65+26|(+/2&|)i.26

Online interpreter

This is actually the program I used to generate the text in the challenge.

Answer 32

Oracle SQL 11.2, 141 138 bytes

SELECT LISTAGG(CHR(l+64)||CHR(MOD(l,26)+65))WITHIN GROUP(ORDER BY l)FROM(SELECT CEIL(LEVEL/13)l FROM DUAL CONNECT BY LEVEL<339)GROUP BY l;

Un-golfed

SELECT LISTAGG(CHR(l+64)||CHR(MOD(l,26)+65))WITHIN GROUP(ORDER BY l)
FROM   (
         SELECT CEIL(LEVEL/13)l 
         FROM   DUAL 
         CONNECT BY LEVEL<339  -- 26*13+1
       )
GROUP BY l                               

Answer 33

MATLAB, 47 38 bytes

a=(65:90)';char(repmat([a a([2:end 1])],1,13))

char(repmat([65:90;[66:90 65]]',1,13))

The first makes a column array of the alphabet in ASCII, appends a shifted copy as a column to its right, replicates the resulting 26*2 array 13 times columnwise, casts to a character array and prints by default.

The second makes a 2*26 array of alphabet and shifted alphabet, transposes it then continues as above.

Answer 34

Neoscript, 59 bytes

a=('A:[]:'Z)+'Aeach n=0:[]:25console:log((a[n]+a[n+1])*13);

Answer 35

PHP, 102 bytes

<?php $a='ABCDEFGHIJKLMNOPQRSTUVWXYZA';$i=-1;while($i++<25){echo str_repeat(substr($a,$i,2),13)."\n";}

Answer 36

Ruby, 41 bytes

26.times{|i|puts [*?A..?Z,?A][i,2]*''*13}

Answer 37

C (86 bytes):

for(int c=-11,n=-26;++n<1;){while(c++){printf("%c%c",90+n,n?91+n:65);}c=-11;puts("");}

My first attempt on a Code Golf challenge.

Some answers are really impressive!

Answer 38

PHP, 65 bytes

Well, this is pretty straight forward:

for(;$i<26;)echo str_repeat(chr(65+$i).chr(65+(++$i%26)),13)."
";

Answer 39

C#, 107 bytes

My first attempt at a submission to PPCG

Golfed:

var l="";int i=0,j=0;for(;i<26;i++){for(;j<26;j++)l+=(char)(((j%2)+i)%26+65);Console.WriteLine(l);l="";j=0;}

Ungolfed:

var l="";
int i=0,j=0;
for(;i<26;i++){
    for(;j<26;j++)l+=(char)(((j%2)+i)%26+65);
        Console.WriteLine(l);
    l="";j=0;
}

Pretty sure this adheres to standards! Would love to hear any potential improvements.

Answer 40

Java 7, 87 bytes

void c(){for(int i=0;i<703;)System.out.print((char)(i++%27>0?65+(i/27+i%27%2)%26:10));}

Based on @orlp's amazing answer.

Ungolfed & test code:

Try it here.

class Main {
  public static void main(String[]a){
    c();
  }

  static void c(){
    for(int i=0; i<703;){
        System.out.print((char)(i++%27 > 0
                                  ? 65 + (i/27+i%27%2)%26
                                  :10));
    }
  }
}

Answer 41

T-SQL 99 90 bytes

Saved 9 bytes thanks to @t-clausen.dk

DECLARE @ INT=65z:PRINT REPLICATE(CHAR(@)+CHAR(IIF(@=90,65,@+1)),13)SET @+=1IF @<=90GOTO z

Ungolfed:

DECLARE @CurrCharacter INT = 65; --ASCII decimal for 'A'
WHILE (@CurrCharacter <=90) --ASCII decimal for 'Z'
BEGIN 
   PRINT REPLICATE(
    REPLACE(CHAR(@CurrCharacter)+CHAR(@CurrCharacter+1),'[','A')
    ,13); --Replicate the current character and its neighbor 13 times. If the neighbor is '[' (ASCII code 91) then replace it with 'A'.
   SET @CurrCharacter+=1; --Go to the next letter
END

Answer 42

Python 2 53 bytes

i=0;exec'print(chr(i+65)+chr(-~i%26+65))*13;i+=1;'*26

Answer 43

Javascript, 98 Bytes

for(var j=371,s="";j<1333;j+=37){for(i=0;i<13;i++)s+=j.toString(36).replace("100","za");s+="<br>"}

Try it here

Answer 44

tcl, 80

time {puts [string repe [format %c%c [expr [incr i]+64] [expr $i%26+65]] 13]} 26

demo

---

tcl, 86

while {[incr i]<27} {puts [string repe [format %c%c [expr $i+64] [expr $i%26+65]] 13]}

demo

Answer 45

Bash + Unix utilities, 53 52 bytes

dc "-e65[d257*1+16 52^65535/*POP1+d91>x]dsxx"|tr [ A

Try it online!

Test run:

dc "-e65[d257*1+16 52^65535/*POP1+d91>x]dsxx"|tr [ A
ABABABABABABABABABABABABAB
BCBCBCBCBCBCBCBCBCBCBCBCBC
CDCDCDCDCDCDCDCDCDCDCDCDCD
DEDEDEDEDEDEDEDEDEDEDEDEDE
EFEFEFEFEFEFEFEFEFEFEFEFEF
FGFGFGFGFGFGFGFGFGFGFGFGFG
GHGHGHGHGHGHGHGHGHGHGHGHGH
HIHIHIHIHIHIHIHIHIHIHIHIHI
IJIJIJIJIJIJIJIJIJIJIJIJIJ
JKJKJKJKJKJKJKJKJKJKJKJKJK
KLKLKLKLKLKLKLKLKLKLKLKLKL
LMLMLMLMLMLMLMLMLMLMLMLMLM
MNMNMNMNMNMNMNMNMNMNMNMNMN
NONONONONONONONONONONONONO
OPOPOPOPOPOPOPOPOPOPOPOPOP
PQPQPQPQPQPQPQPQPQPQPQPQPQ
QRQRQRQRQRQRQRQRQRQRQRQRQR
RSRSRSRSRSRSRSRSRSRSRSRSRS
STSTSTSTSTSTSTSTSTSTSTSTST
TUTUTUTUTUTUTUTUTUTUTUTUTU
UVUVUVUVUVUVUVUVUVUVUVUVUV
VWVWVWVWVWVWVWVWVWVWVWVWVW
WXWXWXWXWXWXWXWXWXWXWXWXWX
XYXYXYXYXYXYXYXYXYXYXYXYXY
YZYZYZYZYZYZYZYZYZYZYZYZYZ
ZAZAZAZAZAZAZAZAZAZAZAZAZA

Answer 46

Windows batch, 155 bytes

@set s=ABCDEFGHIJKLMNOPQRSTUVWXYZA
@set/ac=-1
:L
@set/ac+=1
@call set t=%%s:~%c%,2%%
@for /l %%i in (1,1,13) do @cd|set/p=%t%
@echo(
@if %t% neq ZA @goto l

Answer 47

Excel VBA, 50 Bytes

Anonymous VBE immediate window function that takes no input and outputs a wave to the range [A1:Z26] on the ActiveSheet object

[A1:Z26]="=Char(Mod(Row()+IsEven(Column()),26)+64)

Answer 48

Recursiva, 19 bytes

{B26'P*13Z~}+(C65;}

Try it online!

Answer 49

Pyth, 12 bytes

I haven't been there

VG*13+N@G=hZ

Explanation:

VG       In the lowercase alphabet...
  *13     13 times...
  +N@G=hZ The current item concatenated with alphabet[++Z]

Try it online!

Answer 50

K (oK), 23 bytes

Solution:

`c$65+26#'a,'1_27#a:!26

Try it online!

Explanation:

`c$65+26#'a,'1_27#a:!26 / solution
                    !26 / range 0..25
                  a:    / save as 'a'
               27#      / 27 take, wraps to make ABC...XYZA
             1_         / 1 drop, take off leading A
          a,'           / concatenate each element with each of a (AB,BC,etc)
      26#'              / 26 take each, wraps to get ABABAB... BCBCBC... etc
   65+                  / add 65, vectorised (65=A in ASCII)
`c$                     / cast to characters

Bonus:

Here are a couple of other ways to get the result:

24 chars: Try it online!

`c$65++26#(!26;1_27#!26)

27 chars: Try it online!

26#'+0 1_'26 27#\:`c$65+!26

Answer 51

q/kdb+, 19 bytes

Solution:

26#'.Q.A,'1_27#.Q.A

Explanation:

Shorter and different to my oK solutions as we have a shortcut to the uppercase alphabet by means of .Q.A. As always, interpreted right-to-left

26#'.Q.A,'1_27#.Q.A / solution
               .Q.A / shortcut to uppercase alphabet, ABC..XYZ
            27#     / 27 take, wraps to get ABC...XYZA
          1_        / 1 drop, drop first element to give BCD...XYZA
    .Q.A,'          / concatenate each left/right lists, so AB, BC, CD etc
26#'                / 26 take each, gives ABABA.. BCBCB... etc

Answer 52

Mathematica, 52 bytes

Column[""<>#~Table~13&/@Partition[Alphabet[],2,1,1]]

-1 byte from Martin Ender

Answer 53

Yabasic, 69 bytes

For I=1To 26
For J=0To 12
?Chr$(I+64)+Chr$(Mod(I,26)+65);
Next
?
Next

Try it online!

Answer 54

Visual Basic .NET (Mono), 140 bytes

Module M
Sub Main
Dim I,J,S
For I=1To 26
S=""
For J=0To 11
S+=Chr$(I+64)+Chr$(I Mod 26+65)
Next
Console.WriteLine(S)
Next
End Sub
End Module

Try it online!

Answer 55

MY-BASIC, 77 bytes

For I=1 To 26
For J=0 To 12
Print Chr(I+64)+Chr(I Mod 26+65)
Next
Print;
Next

Try it online!

Answer 56

uBASIC, 83 bytes

0ForI=1To26:ForJ=0To12:?Left$(Chr$(I+64),1)+Left$(Chr$(IMod26+65),1);:NextJ:?:NextI

Try it online!

Answer 57

APL (Dyalog Unicode), 13 bytes^SBCS

⍉(⎕a⌽⍨2|⊢)⌸⎕a

Try it online!

Answer 58

Julia, 51 bytes

!()=join(["$x$(x+1-26(x>89))"^13for x='A':'Z'],"
")

Initial golfing.

Answer 59

C, 77 74 71 bytes

Basically the same as the Python answer inspired by LeakyNun, Thanks to owacoder for puts :

f(i,j){for(i=0;++i<27;puts(""))for(j=13;--j;printf("%c%c",i+64,i%26+65));}

Usage:

f();

While mathematically (26-n)%26 == (-n)%26, this is not true for C, otherwise these two bytes can be shaved off. Using a count up loop for i resolves the problem

Answer 60

Java 8, 139 137 bytes

()->{for(int i=65,j=1;;j++){if(j>25){j=++i<91?1:0;System.out.println();
if(j==0)break;}System.out.print((char)i+""+(char)(i>89?65:i+1));}}

Answer 61

Javascript(ES5), 107 99 bytes

for(var s="",i=-1;++i<676;)i&&!(i%26)&&(s+="\n"),s+=String.fromCharCode((i/26+i%2)%26+65);alert(s);

Answer 62

RETURN, 23 bytes

'A'[␊'B'[␊'A␈13␋␄'␊°␇␂,

Try it here.

NOTE: Use the "Insert String" button and paste the above code in.

Explanation

Basically generates A-Z and B-Z and A at the end on the stack. Then the stack is duplicated 13 times, transposed, joined with a newline, and outputted.

Due to a bug that I just can't fix, 'A'[␊${25@}13␋␄'␊°␇␂, does not work.

Answer 63

C# - 159 138 bytes

var a="ABCDEFGHIJKLMNOPQRSTUVWXYZA";for(int i=0;i<26;i++){for(int j=0;j<14;j++){Console.Write("{0}{1}",a[i],a[i+1]);}Console.WriteLine();}

Answer 64

Javascript (using external library Enumerable) (84 bytes)

    n=>(w=_.Range(0,26)).WriteLine(x=>w.Write("",y=>String.fromCharCode((x+y%2)%26+65)))

Link to lib: https://github.com/mvegh1/Enumerable/

Code explanation: Create a range of ints starting at 0 for count of 26. Store into global variable w. For each, write a new line according to predicate. Predicate states to take "w" and write a joined string based off the passed predicate to Write. Predicate to Write uses an empty string as the join delimiter, and uses the current integer value from WriteLine ("x") and the current integer value from Write ("y") to calculate the correct string at that position

Edit: Removed extra parens to save 2 bytes

Answer 65

JAVA 9, 103 97 bytes

it works on JShell, provided by Java9 SDK.

for(int c=64,i;++c<91;)for(i=0;i<26;)System.out.print((char)((c-13+i%2)%26+65)+(i++<25?"":"\n"))

Answer 66

Pyke, 13 bytes

GGt\a+]w-*,_X

Try it here!

Answer 67

ListSharp, 236 bytes

ROWS x=ROWSPLIT "A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,T,S,U,V,W,X,Y,Z,A" BY [","]
[FOREACH NUMB IN 1 TO 26 AS i]
{
STRG t =""
[FOREACH NUMB IN 1 TO 13 AS j]
{
STRG e=GETLINE x [i]
STRG r=GETLINE x [i+1]
STRG t=t+e+r
}
ROWS s=s+t
}
SHOW=s

Feel free to comment if you want anything to be explained to you

Execution screenshot:

Answer 68

Perl 6, 50 bytes

say .join x 13 for flat('A'..'Z','A').rotor(2=>-1)

Answer 69

EXCEL: 53 bytes

=REPT(CHAR(ROW(A1)+64)&CHAR(MOD(ROW(A1),26)+65),13)

Place in A1 and drag to desired length of wave (in this case, 26, one cell for each letter).

Answer 70

Improving on @gabe3886's answer (new account and not able to comment)

PHP 94 92 Bytes

<?php for($i=0;$i<26;)echo str_repeat(substr('ABCDEFGHIJKLMNOPQRSTUVWXYZA',$i++,2),13)."\n";

However if you suppress notices, it's 92 90 bytes

<?php for(;@$i<26;)echo str_repeat(substr('ABCDEFGHIJKLMNOPQRSTUVWXYZA',@$i++,2),13)."\n";

Answer 71

Logo, 93 bytes

Here's a non-graphical Logo solution. Try it online with Calormen.com's interpreter.

to m:c type char 65+modulo:c 26end
to b:a repeat 13[m:a-1 m:a] pr" end
repeat 26[b repcount]

Answer 72

JavaScript, Z (90) bytes

for(i=65,b=66;i<91;++i,b=b<90?++b:65)console.log(Array(14).join(String.fromCharCode(i,b)))

To learn:

var start = 65,
    end = 90;

for (var i = start, b = i+1; i <= end; ++i) {
    var chars = String.fromCharCode(i, b);
    /* repeat chars 14 times */
    console.log(Array(14).join(chars));
}

Answer 73

VIM, 42

:h<_↵↵↵YZZP:s/./&\r/g↵^25↑y↑pG2↑aa↓^ggy13P

where:

• ↵ is return,
• ^ is ctrl + v
• ↑ is the up arrow
• ↓ is escape

I'm sure this can be golfed more. I'm new to VIM so any suggestions are appreciated.

Answer 74

python 3, 92 90 bytes

a=65
b=66
for i in range(312):
    if a>89:b=65
    print(chr(a)+chr(b),end="")
    if (i+1)%12<1:
        a+=1
        b+=1
        print()

python 2, 80 bytes

a=65
b=66
for i in range(312):
    if a>89:b=65
    print chr(a)+chr(b),
    if (i+1)%12<1:
        a+=1
        b+=1
        print

This program outputs AB AB AB AB... rather than ABABABAB... I'm not sure if this is allowed, but it's the best I can come up with.

EDIT:

Thanks @User902383 for you comment on @TAsk's post allowing me to shave off 2 bytes.

And thanks @NoOneIsHere for suggesting that I move to python 2 instead of 3, I've included a second program in python 2 with a new byte count.

Answer 75

Scala, 64 bytes

Can anyone improve on this?

(('A'to'Z'):+'A').sliding(2).map(_.mkString*13).foreach(println)

Answer 76

Python 2.7, 65 bytes

Python 2 alternative using a recursive function

def l(a=0):
 print(chr(a+65)+chr(-~a%26+65))*13
 if a<25:l(-~a)

Answer 77

Vitsy, 29 bytes

So, instead of doing the typical thing, I used my two-dimensional stacking to generate the alphabets and then offset them by one from each other, alternating back and forth between them.

9a*d5*Hd\[:{:}]Y?y\[y\[O?]aO]

9a*d5*H                        Push an alphabet to the stack.
9a*                                 Push 90 to the stack (character code 'Z')
   d5*                              Push 65 to the stack (character code 'A')
      H                             Pop a, b, push range (a, b)

       d\[:{:}]                Establish the other stacks, while alternating.
       d\[    ]                     Do the bracketed code 13 times.
          : :                       Clone the stack.
           {                        Put the top item of the stack on the bottom.
             }                      Put the bottom item of the stack on the top.
               Y                    Discard a stack. (13*2+1-1 = 26)
                ?                   Rotate right a stack (we start on 'A' now)
                 y\[y\[O?]aO]  Output.
                 y\[        ]       Repeat the code in brackets number of stacks times (26).
                    y\[  ]          Repeat the code in brackets number of stack times (26).
                       O            Pop a, print a as a character.
                        ?           Go right a stack.
                          aO        Output a newline.

Try it online!

Answer 78

PHP, 70 66 64 Bytes

<?$a=A;$b=B;while($a!=AA)echo str_repeat($a++.($b++)[0],13)."
";

3 bytes short (if I would remove the <? as well) from @insertusernamehere answer. So close!

EDIT: Actually got it to 66 bytes (64 without the <?)! Doing A and B without quotes actually seem to work. Seems to be the shortest PHP one as time of write :D

EDIT 2: Also removed " " from AA. Still seems to be working.

Answer 79

Bash, 149, 115, 111, 106 bytes

for i in {0..25};{
printf $(printf %b%b \\`printf %o $[i+65]` \\`printf %o $[-~i%26+65]`)%.s {a..m};echo
}

(thanks @manatwork, saved 34, 4 more bytes)

Bash, 140 bytes

(thanks @steeldriver)

for i in {0..25}; do printf "$(printf '%b%b' \\$(printf '%03o' $((i+65))) \\$(printf '%03o' $((-~i%26+65))))%.0s" {1..13}; printf \\n; done

Save to <file> and run as: /bin/bash <file>

Answer 80

GNU sed, 95 bytes

s,^,@@@@@@@@@@@@@,;s,@,AB,g
:;p
y,ABCDEFGHIJKLMNOPQRSTUVWXYZ,BCDEFGHIJKLMNOPQRSTUVWXYZA,
/^Z/!b

I wish the 'y' command had this syntax: y,A-Z,B-ZA,.

Answer 81

Python, 56

for k in range(26):print(chr(k+65)+chr((k+1)%26+65))*13

Answer 82

PHP, 52 bytes

for($a=A;$a!=AA;)echo str_pad("\n",27,$a++.$a[0],0);

Can JavaScript beat this? Run with -r.

Answer 83

PHP, 78, 72, 67 bytes

<?php $s='A';while($s!='AA')echo str_repeat($s++.(--$s)[0],13)."
";

Try it online!