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 A246331 #19 Mar 17 2015 23:49:45 %S A246331 1,9,25,49,89,113,161,233,345,369,417,489,609,681,825,1041,1369,1393, %T A246331 1441,1513,1633,1705,1849,2065,2401,2473,2617,2833,3193,3409,3841, %U A246331 4489,5465,5489,5537,5609,5729,5801,5945,6161,6497,6569,6713,6929,7289,7505,7937 %N A246331 Total number of ON cells at stage 2n of two-dimensional 5-neighbor outer totalistic cellular automaton defined by "Rule 465". %C A246331 The number of ON cells at stage 2n+1 is infinite. %C A246331 This is a bisection of A147562. %C A246331 The sequence b(n) defined by b(n) = number of ON cells at stage n if n is even, b(n) = number of OFF cells at stage n if n is odd coincides with A147562, and has a simple formula. %D A246331 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; pp. 173-175. %H A246331 N. J. A. Sloane, <a href="/A246331/a246331.pdf">Illustration of first 24 generations</a> %H A246331 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 A246331 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %t A246331 Map[Function[Apply[Plus, Flatten[ #1]]], CellularAutomaton[{ 465, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 130]] (* then take every other term *) %t A246331 ArrayPlot /@ CellularAutomaton[{465, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, 23] %Y A246331 Cf. A147562, A169699, A246316, A246318, A246325, A246326, ... %K A246331 nonn %O A246331 0,2 %A A246331 _N. J. A. Sloane_, Aug 30 2014