A266626 - OEIS

%I #6 Jan 02 2016 03:59:46

%S 1,1,4,2,5,7,8,8,7,13,9,12,11,18,15,18,14,23,16,22,15,30,23,23,20,36,

%T 18,30,32,30,30,34,28,37,33,44,27,52,25,53,32,47,38,54,28,62,36,57,38,

%U 61,43,59,39,65,43,65,44,74,51,67,48,79,40,79,41,82,50

%N Number of ON (black) cells in the n-th iteration of the "Rule 45" elementary cellular automaton starting with a single ON (black) cell.

%D S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

%H G. C. Greubel, <a href="/A266626/b266626.txt">Table of n, a(n) for n = 0..2500</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=45; 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[Total[catri[[k]]],{k,1,rows}] (* Number of Black cells in stage n *)

%Y Cf. A266619.

%K nonn,easy

%O 0,3

%A _Robert Price_, Jan 01 2016