%I #7 Jan 16 2016 10:33:56
%S 1,1,2,2,7,10,15,15,28,39,52,59,76,87,100,100,129,156,185,208,241,268,
%T 297,312,353,388,425,448,489,516,545,545,606,665,726,781,846,905,966,
%U 1013,1086,1153,1222,1277,1350,1409,1470,1501,1590,1673,1758,1829,1918
%N Total number of ON (black) cells after n iterations of the "Rule 129" elementary cellular automaton starting with a single ON (black) cell.
%D S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
%H Robert Price, <a href="/A267446/b267446.txt">Table of n, a(n) for n = 0..1000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>
%H <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%t rule=129; rows=20; ca=CellularAutomaton[rule,{{1},0},rows-1,{All,All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]],{rows-k+1,rows+k-1}],{k,1,rows}]; (* Truncated list of each row *) nbc=Table[Total[catri[[k]]],{k,1,rows}]; (* Number of Black cells in stage n *) Table[Total[Take[nbc,k]],{k,1,rows}] (* Number of Black cells through stage n *)
%Y Cf. A267417.
%K nonn,easy
%O 0,3
%A _Robert Price_, Jan 15 2016