%I #7 Jan 12 2016 00:05:38
%S 0,3,2,5,6,9,8,11,14,9,12,15,20,15,18,21,30,9,28,15,32,27,30,33,44,15,
%T 38,25,46,33,40,43,62,9,60,15,64,27,62,33,72,27,58,45,74,45,60,63,92,
%U 15,86,25,90,45,84,55,102,33,84,55,100,63,82,85,126,9
%N Number of OFF (white) cells in the n-th iteration of the "Rule 105" 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="/A267150/b267150.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=105; 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[Length[catri[[k]]]-nbc[[k]],{k,1,rows}] (* Number of White cells in stage n *)
%Y Cf. A267145.
%K nonn,easy
%O 0,2
%A _Robert Price_, Jan 11 2016