This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A175000 #9 Nov 03 2024 16:44:46
%S A175000 0,0,0,2,1,4,4,9,9,25,44,111,218
%N A175000 Number of stable n-celled patterns ("still lifes") in the HighLife (B36/S23) cellular automaton.
%C A175000 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 A175000 LifeWiki, <a href="https://conwaylife.com/wiki/OCA:HighLife">HighLife</a>
%e A175000 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 A175000 Cf. A019473, A166476
%K A175000 hard,more,nonn
%O A175000 1,4
%A A175000 _Christian Schroeder_, Apr 03 2010