login
Total number of OFF (white) cells after n iterations of the "Rule 137" elementary cellular automaton starting with a single ON (black) cell.
1

%I #8 Jan 17 2016 09:50:56

%S 0,3,6,11,14,19,25,33,38,44,52,60,68,79,90,103,112,123,134,147,161,

%T 177,191,205,218,231,248,270,290,306,323,347,366,380,399,424,442,462,

%U 487,511,530,554,585,612,638,662,684,716,747,775,799,828,862,892,923

%N Total number of OFF (white) cells after n iterations of the "Rule 137" 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="/A267519/b267519.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=137; 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 *) nwc=Table[Length[catri[[k]]]-nbc[[k]],{k,1,rows}]; (* Number of White cells in stage n *) Table[Total[Take[nwc,k]],{k,1,rows}] (* Number of White cells through stage n *)

%Y Cf. A267463.

%K nonn,easy

%O 0,2

%A _Robert Price_, Jan 16 2016