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Number of n-celled quasi still lifes in Conway's Game of Life, up to rotation and reflection.
2

%I #12 Dec 11 2019 07:44:02

%S 0,0,0,0,0,0,0,6,13,57,141,465,1224,3956,11599,36538,107415,327250,

%T 972040,2957488,8879327,26943317

%N Number of n-celled quasi still lifes in Conway's Game of Life, up to rotation and reflection.

%C A quasi still life is a still life made up of two or more strict still lifes (A019473) that share at least 1 neighboring dead cell, but those cells still remain dead due to underpopulation just like if we were to separate those component strict still lifes. Contrast with pseudo still lifes (A056613), where the component strict still lifes share at least 1 neighboring dead cell that remains dead, but the reason shifts from underpopulation in the strict still lifes to overpopulation in the combined pattern.

%H LifeWiki, <a href="https://www.conwaylife.com/wiki/Still_life#Quasi_still_lifes">quasi still lifes</a>

%e When n = 8, the 6 quasi still lifes are the various arrangements of blocks and tubs in which they share a neighbor, but that neighbor remains dead due to underpopulation. In the diagrams below, "." is a dead cell, "o" is a live cell, and "*" is a dead neighboring cell that makes the pattern a quasi still life:

%e .o...o.

%e o.o*o.o

%e .o...o.

%e .

%e .o.....

%e o.o*.o.

%e .o.*o.o

%e .....o.

%e .

%e oo...

%e oo...

%e ..*..

%e ...oo

%e ...oo

%e .

%e oo....

%e oo....

%e ..*.o.

%e ...o.o

%e ....o.

%e .

%e .o.....

%e o.o....

%e .o.*.o.

%e ....o.o

%e .....o.

%e .

%e .o....

%e o.o...

%e .o.*..

%e ..*.o.

%e ...o.o

%e ....o.

%Y Cf. A019473, A056613.

%K nonn,hard,more

%O 1,8

%A _Nathaniel Johnston_, Dec 09 2019