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 A267935 Decimal representation of the n-th iteration of the "Rule 249" elementary cellular automaton starting with a single ON (black) cell. 1
 1, 1, 27, 127, 511, 2047, 8191, 32767, 131071, 524287, 2097151, 8388607, 33554431, 134217727, 536870911, 2147483647, 8589934591, 34359738367, 137438953471, 549755813887, 2199023255551, 8796093022207, 35184372088831, 140737488355327, 562949953421311 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 REFERENCES S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55. LINKS Robert Price, Table of n, a(n) for n = 0..1000 Eric Weisstein's World of Mathematics, Elementary Cellular Automaton S. Wolfram, A New Kind of Science FORMULA Conjectures from Colin Barker, Jan 23 2016 and Apr 20 2019: (Start) a(n) = 5*a(n-1)-4*a(n-2) for n>4. G.f.: (1-4*x+26*x^2-4*x^3-16*x^4) / ((1-x)*(1-4*x)). (End) Empirical a(n) = 2^(2*n+1) - 1 for n>2. - Colin Barker, Nov 26 2016 and Apr 20 2019 MATHEMATICA rule=249; 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 *) Table[FromDigits[catri[[k]], 2], {k, 1, rows}]   (* Decimal Representation of Rows *) CROSSREFS Cf. A267927. Sequence in context: A044359 A044740 A026917 * A048615 A124955 A126414 Adjacent sequences:  A267932 A267933 A267934 * A267936 A267937 A267938 KEYWORD nonn,easy AUTHOR Robert Price, Jan 22 2016 STATUS approved

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Last modified December 7 17:41 EST 2019. Contains 329847 sequences. (Running on oeis4.)