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A289769 Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 598", based on the 5-celled von Neumann neighborhood.

%I A289769 #8 Feb 16 2025 08:33:49
%S A289769 1,2,6,12,20,40,88,176,272,544,1760,3520,4416,8832,28032,56064,65792,
%T A289769 131584,396800,793600,1332224,2664448,5986304,11972608,16846848,
%U A289769 33693696,101638144,203276288,340869120,681738240,1533902848,3067805696,4295032832,8590065664
%N A289769 Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 598", based on the 5-celled von Neumann neighborhood.
%C A289769 Initialized with a single black (ON) cell at stage zero.
%D A289769 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 170.
%H A289769 Robert Price, <a href="/A289769/b289769.txt">Table of n, a(n) for n = 0..126</a>
%H A289769 Robert Price, <a href="/A289769/a289769.tmp.txt">Diagrams of first 20 stages</a>
%H A289769 N. J. A. Sloane, <a href="http://arxiv.org/abs/1503.01168">On the Number of ON Cells in Cellular Automata</a>, arXiv:1503.01168 [math.CO], 2015
%H A289769 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H A289769 S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>
%H A289769 Wolfram Research, <a href="http://atlas.wolfram.com/">Wolfram Atlas of Simple Programs</a>
%H A289769 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H A289769 <a href="https://oeis.org/wiki/Index_to_2D_5-Neighbor_Cellular_Automata">Index to 2D 5-Neighbor Cellular Automata</a>
%H A289769 <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%t A289769 CAStep[rule_, a_] := Map[rule[[10 - #]] &, ListConvolve[{{0, 2, 0},{2, 1, 2}, {0, 2, 0}}, a, 2],{2}];
%t A289769 code = 598; stages = 128;
%t A289769 rule = IntegerDigits[code, 2, 10];
%t A289769 g = 2 * stages + 1; (* Maximum size of grid *)
%t A289769 a = PadLeft[{{1}}, {g, g}, 0,Floor[{g, g}/2]]; (* Initial ON cell on grid *)
%t A289769 ca = a;
%t A289769 ca = Table[ca = CAStep[rule, ca], {n, 1, stages + 1}];
%t A289769 PrependTo[ca, a];
%t A289769 (* Trim full grid to reflect growth by one cell at each stage *)
%t A289769 k = (Length[ca[[1]]] + 1)/2;
%t A289769 ca = Table[Table[Part[ca[[n]] [[j]],Range[k + 1 - n, k - 1 + n]], {j, k + 1 - n, k - 1 + n}], {n, 1, k}];
%t A289769 Table[FromDigits[Part[ca[[i]] [[i]], Range[i, 2 * i - 1]], 10], {i, 1, stages - 1}]
%Y A289769 Cf. A289766, A289767, A289768.
%K A289769 nonn,easy
%O A289769 0,2
%A A289769 _Robert Price_, Jul 12 2017