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 A253090 #17 Mar 17 2015 23:49:46
%S A253090 1,9,8,32,16,88,16,104,16,136,72,312,56,360,76,468,76,444,156,708,152,
%T A253090 928,164,996,156,924,292,1316,256,1520,348,1676,304,1768,400,1928,408,
%U A253090 2040,524,2628,516,2684,688,3272,744,3872,684,3692,756,3724,840,4080
%N A253090 Number of ON cells at generation n of 9-celled totalistic CA defined by Rule 614.
%C A253090 A cell turns ON at generation n iff it was OFF at generation n-1 and exactly 1 or 3 of its 8 neighbors were ON, or if it was ON and exactly 0, 2 or 4 of its 8 neighbors were ON.
%C A253090 Note that although A072272 is an "odd-rule" CA, this one is not.
%H A253090 N. J. A. Sloane, <a href="/A253090/a253090.png">Illustration of generations 0-15</a>
%H A253090 N. J. A. Sloane, <a href="/A253090/a253090_1.png">Illustration of generation 31</a>
%H A253090 N. J. A. Sloane, <a href="http://arxiv.org/abs/1503.01168">On the Number of ON Cells in Cellular Automata</a>, arXiv:1503.01168, 2015
%H A253090 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%F A253090 It would be nice to have a recurrence.
%t A253090 Map[Function[Apply[Plus, Flatten[#1]]],
%t A253090 CellularAutomaton[{614, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 66]]
%t A253090 ArrayPlot /@ CellularAutomaton[{614, {2, {{2, 2, 2}, {2, 1, 2}, {2, 2, 2}}}, {1, 1}}, {{{1}}, 0}, 15]
%Y A253090 Cf. A072272 (5-neighbor analog).
%K A253090 nonn
%O A253090 0,2
%A A253090 _N. J. A. Sloane_, Feb 12 2015