Sawtooth 181

Sawtooth 181 is a diagonal sawtooth discovered on April 28th, 2015 by Chris Cain,[1] based on a suggestion by Dongook Lee and initial two-glider shotgun constructed by Brett Berger. It was the smallest known sawtooth in terms of its minimum repeating population of 181, until being superseded by Sawtooth 177 (which differs only in the phases of the constituent guns).

Sawtooth 181
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Pattern type Sawtooth
Number of cells 181
Bounding box 78×87
Expansion factor 121
Discovered by Chris Cain
Year of discovery 2015

The sawtooth functions by letting two glider streams of period 120 generated by two Simkin glider guns (which were first discovered the same day) retract a block, created by collision with a spark from a 58P5H1V1, one cell at a time. The retracted block is deleted via interaction with a pentadecathlon, and the streams are allowed to return to the now-farther-away 58P5H1V1 to create another block.

Population

The population is equal to 181 at generations 0, 6960, 849120, 102750480, ..., 58 * (121n - 1), ..., giving an expansion factor of 121.

gollark: That is, a character is a u32 or maybe something else.
gollark: Because a "char" is really a u32, accurately speaking.
gollark: `char` bad, `u8` good.
gollark: Do you *need* that?
gollark: Well, "char" is wrong in C?

See also

References
  1. Chris Cain (April 28, 2015). "Re: Smaller sawtooth". ConwayLife.com forums. Retrieved on July 3, 2016.
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