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%I #16 Apr 19 2019 11:49:00
%S 1,4,18,72,294,1168,4686,18728,74886,299632,1198414,4793384,19174278,
%T 76696176,306782542,1227136040,4908536710,19634129520,78536565070,
%U 314146200616,1256584663942,5026339031664,20105355649358,80421421489192,321685688963974
%N Decimal representation of the n-th iteration of the "Rule 131" 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="/A267450/b267450.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 Empirical g.f.: (1+2*x^2-8*x^3+5*x^4-24*x^5+12*x^6-56*x^7+32*x^8) / ((1-x)*(1+x)*(1-2*x)*(1-4*x)*(1+x^2)*(1+2*x+4*x^2)). - _Colin Barker_, Jan 15 2016 and Apr 19 2019
%t rule=131; 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 *) Table[FromDigits[catri[[k]],2],{k,1,rows}] (* Decimal Representation of Rows *)
%Y Cf. A267418.
%K nonn
%O 0,2
%A _Robert Price_, Jan 15 2016
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