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 A166476 #4 Nov 03 2024 16:43:03
%S A166476 0,2,1,3,4,9,10,27,48,126
%N A166476 Number of stable n-celled patterns ("still lifes") in the 2x2 (B36/S125) cellular automaton.
%C A166476 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 A166476 LifeWiki, <a href="https://conwaylife.com/wiki/OCA:2%C3%972">2x2</a>
%e A166476 a(3) = 1 because there is only one distinct still life with three cells: a diagonal line of length three.
%Y A166476 Cf. A019473
%K A166476 hard,more,nonn
%O A166476 1,2
%A A166476 _Nathaniel Johnston_, Oct 14 2009