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 A270234 Partial sums of the number of active (ON,black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 133", based on the 5-celled von Neumann neighborhood. 1
 1, 9, 13, 53, 70, 170, 195, 379, 435, 752, 800, 1229, 1349, 1998, 2070, 2903, 3031, 4104, 4272, 5505, 5817, 7446, 7558, 9603, 9883, 12043, 12448, 15000, 15393, 18477, 18854, 22250, 22779, 26651, 27188, 31380, 32161, 37033, 37658, 43082, 43799, 49703, 50564 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Initialized with a single black (ON) cell at stage zero. REFERENCES S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 170. LINKS Robert Price, Table of n, a(n) for n = 0..128 N. J. A. Sloane, On the Number of ON Cells in Cellular Automata, arXiv:1503.01168 [math.CO], 2015 Eric Weisstein's World of Mathematics, Elementary Cellular Automaton S. Wolfram, A New Kind of Science MATHEMATICA CAStep[rule_, a_]:=Map[rule[[10-#]]&, ListConvolve[{{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}, a, 2], {2}]; code=133; stages=128; rule=IntegerDigits[code, 2, 10]; g=2*stages+1; (* Maximum size of grid *) a=PadLeft[{{1}}, {g, g}, 0, Floor[{g, g}/2]]; (* Initial ON cell on grid *) ca=a; ca=Table[ca=CAStep[rule, ca], {n, 1, stages+1}]; PrependTo[ca, a]; (* Trim full grid to reflect growth by one cell at each stage *) k=(Length[ca[[1]]]+1)/2; ca=Table[Table[Part[ca[[n]][[j]], Range[k+1-n, k-1+n]], {j, k+1-n, k-1+n}], {n, 1, k}]; on=Map[Function[Apply[Plus, Flatten[#1]]], ca] (* Count ON cells at each stage *) Table[Total[Part[on, Range[1, i]]], {i, 1, Length[on]}] (* Sum at each stage *) CROSSREFS Cf. A270232. Sequence in context: A146016 A146128 A146039 * A270718 A270459 A270948 Adjacent sequences:  A270231 A270232 A270233 * A270235 A270236 A270237 KEYWORD nonn,easy AUTHOR Robert Price, Mar 13 2016 STATUS approved

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Last modified December 4 11:50 EST 2021. Contains 349486 sequences. (Running on oeis4.)