42P38

42P38
x = 27, y = 25, rule = B3/S23 13bo$12bo2bo$12bo2bo2bo$14bo3bo$18bo3$o$3o$3bo14bo$2b2o14b2o$17b2o2$8b 2o$7b2o14b2o$8bo14bo$24b3o$26bo3$8bo$8bo3bo$8bo2bo2bo$11bo2bo$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 500 THUMBSIZE 3 ZOOM 18 GPS 19 LOOP 38 ]]
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Pattern type	Oscillator
Number of cells	42
Bounding box	25 × 27
Period	38 (mod: 38)
Heat	45.5
Volatility	0.93 | 0.87
Kinetic symmetry	Unspecified
Discovered by	Mitchell Riley
Year of discovery	2023
Rules Outer-totalistic rules B3/S23 – B38/S238 # of rules 22 = 4 Isotropic rules B3/S23 – B34e5ce6n7c8/S234cey5e6i7e8
Pattern files RLE 42p38.rle
Identifiers apgcode xp38_y2178czy8s4cy1szsoyfesz01sy1ogszy9o8gzyb32

42P38 is a small period-38 oscillator found by Mitchell Riley on April 21, 2023. With only 42 cells, it is the smallest known period-38 oscillator by population; surpassing 44P38. It consists of an R-pentomino turning into an octomino II via fishhook, then turning back into an R-pentomino via a combination of a transparent blinker plus toad catalyst and hitting a second copy of itself.

It is a delayed domino sparker, allowing for the construction of some LCM oscillators.

LCM oscillators

The LCM oscillators below are listed due to being the smallest known ones by population, while also satisfying the condition that at least one cell oscillates at the full period.

x = 30, y = 25, rule = B3/S23 13bo$12bo2bo$12bo2bo2bo$14bo3bo6b2o$18bo5bo2bo$24bobo2bo$25bo$o25b2obo $3o25bo$3bo14bo$2b2o14b2o$17b2o2$8b2o$7b2o14b2o$8bo14bo$24b3o$26bo3$8b o$8bo3bo$8bo2bo2bo$11bo2bo$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 HEIGHT 400 ZOOM 14 GPS 24 THEME Book AUTOSTART STOP 76 ]] 54P76 with mold (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

x = 32, y = 25, rule = B3/S23 13bo$12bo2bo14b2o$12bo2bo2bo9bob2o$14bo3bo8bo$18bo11bo$26b2obo$26b2o$o $3o$3bo14bo$2b2o14b2o$17b2o2$8b2o$7b2o14b2o$8bo14bo$24b3o$26bo3$8bo$8b o3bo$8bo2bo2bo$11bo2bo$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 HEIGHT 400 ZOOM 14 GPS 24 THEME Book AUTOSTART STOP 152 ]] 54P152 with figure eight (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

x = 39, y = 25, rule = B3/S23 13bo$12bo2bo13b2o5b2o$12bo2bo2bo10b2o5b2o$14bo3bo$18bo2$28b3o5b3o$o27b o2bo3bo2bo$3o26bo7bo$3bo14bo11bobobobo$2b2o14b2o$17b2o12b2ob2o2$8b2o$ 7b2o14b2o5bo5bo$8bo14bo5b2o5b2o$24b3o$26bo3$8bo$8bo3bo$8bo2bo2bo$11bo 2bo$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 HEIGHT 400 ZOOM 12 GPS 24 THEME Book AUTOSTART STOP 266 ]] 76P266 with 34P14 shuttle (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

x = 41, y = 29, rule = B3/S23 22b2o$22b2o$22b2o$22bo13bo2bo$13bo7bobo12bo$12bo2bo6bobob3o6bo4bo$12bo 2bo2bo4bob4o5bobo2b2o$14bo3bo5bo7b2obo$18bo$28bo$27bo4bo2bo$o27bo5b2o$ 3o$3bo14bo9b2o$2b2o14b2o8b2o$17b2o2$8b2o$7b2o14b2o$8bo14bo$24b3o$26bo 3$8bo$8bo3bo$8bo2bo2bo$11bo2bo$13bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 HEIGHT 400 ZOOM 12 GPS 24 THEME Book AUTOSTART STOP 342 ]] 85P342 with p18 bi-block hassler (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here

External links

• 42P38 at Adam P. Goucher's Catagolue