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%I #9 Nov 03 2024 16:44:46
%S 0,0,0,2,1,4,4,9,9,25,44,111,218
%N Number of stable n-celled patterns ("still lifes") in the HighLife (B36/S23) cellular automaton.
%C Counts only distinct strict still lifes; reflections and rotations are removed. Pseudo-still lifes (e.g., patterns made up of two disjoint still lifes) are not counted.
%H LifeWiki, <a href="https://conwaylife.com/wiki/OCA:HighLife">HighLife</a>
%e a(4)=2 because there are only two still-lives with four cells: the block (a 2x2 block) and the tub (four cells bordering all four sides of an empty spot).
%Y Cf. A019473, A166476
%K hard,more,nonn
%O 1,4
%A _Christian Schroeder_, Apr 03 2010