Quad

	Quad
	<a href="/wiki/File:Quad.png" class="image" title="Quad image"><img alt="Quad image" src="/w/images/6/69/Quad.png" decoding="async" width="129" height="129" /></a>
	<a href="/wiki/File:Quad.png" class="image" title="Quad image"><img alt="Quad image" src="/w/images/6/69/Quad.png" decoding="async" width="129" height="129" /></a>
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Pattern type	Oscillator
Oscillator type	Muttering moat
Family	Barberpole
Number of cells	16
Bounding box	6×6
Period	2
Mod	1
Heat	8
Volatility	0.40
Strict volatility	0.40
Rotor type	Clock
Discovered by	Robert Kraus
Year of discovery	1971
Rules
Outer-totalistic rules	B3/S23 – B35678/S02345678
Important rules	Conway Life, HighLife
# of rules	210 = 1024
Isotropic rules	B3y/S2ae3n – B1e2cin34-r5678/S01e2345678
Glider synthesis
Fewest gliders	10
Catagolue-generated RLE	quad_synth.rle
Uploaded synthesis RLE	quad_synth.rle
Pattern files
Plaintext	quad.cells
RLE	quad.rle
Identifiers
apgcode	xp2_j5g29jz11w11
Pentadecathlon ID	16P2.19

Quad (or barberpole intersection^[1]) is a period-2 oscillator and muttering moat that was found in April 1971 by Robert Kraus.^[2] It has the same rotor as the clock. It and mold are the only flippers that fit inside a 6×6 bounding box; however, mold is period 4.

This oscillator first occurred naturally on December 28, 2015, in a soup submitted to Catagolue by Adam P. Goucher. A 12-glider synthesis was constructed the next day by Tanner Jacobi.^[3]

References

↑ Eric Weisstein. "Quad". Eric Weisstein's Treasure Trove of Life. Retrieved on May 1, 2009.
↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
↑ Tanner Jacobi (December 29, 2015). Re: Soup search results (discussion thread) at the ConwayLife.com forums