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 A265206 #12 Feb 16 2025 08:33:27
%S A265206 1,1,4,4,11,13,18,20,29,35,40,50,63,69,80,90,105,115,134,144,167,177,
%T A265206 194,214,233,249,274,292,311,331,356,370,407,427,454,480,515,535,572,
%U A265206 602,643,667,700,736,775,801,846,882,919,957,998,1034,1083,1127,1156
%N A265206 Total number of ON (black) cells after n iterations of the "Rule 73" elementary cellular automaton starting with a single ON (black) cell.
%D A265206 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
%H A265206 Robert Price, <a href="/A265206/b265206.txt">Table of n, a(n) for n = 0..999</a>
%H A265206 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H A265206 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H A265206 <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%t A265206 rule = 73; rows = 30; Table[Total[Take[Table[Total[Table[Take[CellularAutomaton[rule,{{1},0},rows-1,{All,All}][[k]],{rows-k+1,rows+k-1}],{k,1,rows}][[k]]],{k,1,rows}],k]],{k,1,rows}]
%Y A265206 Cf. A245549, A262448, A265122, A265156, A265205.
%K A265206 nonn,easy
%O A265206 0,3
%A A265206 _Robert Price_, Dec 04 2015