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%I #14 Apr 19 2019 07:11:35
%S 0,2,2,2,3,3,6,2,11,4,13,2,19,4,21,2,27,4,29,2,35,4,37,2,43,4,45,2,51,
%T 4,53,2,59,4,61,2,67,4,69,2,75,4,77,2,83,4,85,2,91,4,93,2,99,4,101,2,
%U 107,4,109,2,115,4,117,2,123,4,125,2,131,4,133,2
%N Number of OFF (white) cells in the n-th iteration of the "Rule 107" 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="/A267160/b267160.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>
%F Conjectures from _Colin Barker_, Jan 11 2016 and Apr 19 2019: (Start)
%F a(n) = a(n-2)+a(n-4)-a(n-6) for n>11.
%F G.f.: x*(2+2*x+x^3-x^4+x^5-x^6+4*x^7+x^8-x^9-x^10+x^11) / ((1-x)^2*(1+x)^2*(1+x^2)).
%F (End)
%t rule=107; 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. A267152.
%K nonn,easy
%O 0,2
%A _Robert Price_, Jan 11 2016
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