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 A267885 Binary representation of the n-th iteration of the "Rule 235" elementary cellular automaton starting with a single ON (black) cell. 1
 1, 100, 11011, 1111111, 111111111, 11111111111, 1111111111111, 111111111111111, 11111111111111111, 1111111111111111111, 111111111111111111111, 11111111111111111111111, 1111111111111111111111111, 111111111111111111111111111, 11111111111111111111111111111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 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 Index entries for linear recurrences with constant coefficients, signature (101,-100). FORMULA From Colin Barker, Jan 22 2016: (Start) a(n) = 101*a(n-1)-100*a(n-2) for n>4. G.f.: (1-x+1011*x^2+9000*x^3-10000*x^4) / ((1-x)*(1-100*x)). (End) MATHEMATICA rule=235; 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]]], {k, 1, rows}]   (* Binary Representation of Rows *) PROG (PARI) Vec((1-x+1011*x^2+9000*x^3-10000*x^4)/((1-x)*(1-100*x)) + O(x^20)) \\ Colin Barker, Jan 22 2016 CROSSREFS Cf. A267869. Sequence in context: A267674 A267846 A267684 * A151648 A013747 A065447 Adjacent sequences:  A267882 A267883 A267884 * A267886 A267887 A267888 KEYWORD nonn,easy AUTHOR Robert Price, Jan 21 2016 STATUS approved

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Last modified March 26 01:08 EDT 2019. Contains 321479 sequences. (Running on oeis4.)