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 A269708 Number of active (ON,black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 14", based on the 5-celled von Neumann neighborhood. 0
 1, 5, 20, 76, 292, 1132, 4420, 17356, 68452, 270892, 1074820, 4273036, 17013412, 67817452, 270561220, 1080119116 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Initialized with a single black (ON) cell at stage zero. Rules 46, 142 and 174 also generate this sequence. REFERENCES S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 170. LINKS Table of n, a(n) for n=0..15. 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 Index entries for sequences related to cellular automata Index to 2D 5-Neighbor Cellular Automata Index to Elementary Cellular Automata FORMULA Conjectures from Colin Barker, Mar 08 2016: (Start) a(n) = 4*3^(n-2)+4^n for n>1. a(n) = 7*a(n-1)-12*a(n-2) for n>3. G.f.: (1-2*x-3*x^2-4*x^3) / ((1-3*x)*(1-4*x)). (End) MATHEMATICA rule=14; stages=300; ca=CellularAutomaton[{rule, {2, {{0, 2, 0}, {2, 1, 2}, {0, 2, 0}}}, {1, 1}}, {{{1}}, 0}, stages]; (* Start with single black cell *) on=Map[Function[Apply[Plus, Flatten[#1]]], ca] (* Count ON cells at each stage *) Part[on, 2^Range[0, Log[2, stages]]] (* Extract relevant terms *) CROSSREFS Cf. A269707. Sequence in context: A005283 A057552 A300918 * A295347 A270985 A289786 Adjacent sequences: A269705 A269706 A269707 * A269709 A269710 A269711 KEYWORD nonn,more AUTHOR Robert Price, Mar 04 2016 EXTENSIONS a(9)-a(15) from Lars Blomberg, Apr 12 2016 STATUS approved

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Last modified May 29 22:36 EDT 2024. Contains 372954 sequences. (Running on oeis4.)