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 A279151 Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood. 4
 1, 0, 5, 4, 1, 56, 21, 148, 1, 1016, 21, 3988, 257, 14584, 5397, 38036, 1, 262136, 21, 1048468, 257, 4192504, 5397, 16749716, 65537, 66650104, 1376277, 261422996, 16843009, 955840760, 353703189, 2492765332, 1, 17179869176, 21, 68719476628, 257, 274877905144 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 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..126 Robert Price, Diagrams of first 20 stages 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 Wolfram Research, Wolfram Atlas of Simple Programs MATHEMATICA CAStep[rule_, a_] := Map[rule[[10 - #]] &, ListConvolve[{{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}, a, 2], {2}]; code = 145; 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)/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}]; Table[FromDigits[Part[ca[[i]] [[i]], Range[i, 2 * i - 1]], 2], {i , 1, stages - 1}] CROSSREFS Cf. A279149, A278584, A279150. Sequence in context: A152862 A108440 A102220 * A224228 A286680 A201680 Adjacent sequences:  A279148 A279149 A279150 * A279152 A279153 A279154 KEYWORD nonn,easy AUTHOR Robert Price, Dec 06 2016 STATUS approved

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Last modified September 16 21:28 EDT 2021. Contains 347473 sequences. (Running on oeis4.)