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 A266302 Decimal representation of the n-th iteration of the "Rule 15" elementary cellular automaton starting with a single ON (black) cell. 1
 1, 6, 1, 126, 1, 2046, 1, 32766, 1, 524286, 1, 8388606, 1, 134217726, 1, 2147483646, 1, 34359738366, 1, 549755813886, 1, 8796093022206, 1, 140737488355326, 1, 2251799813685246, 1, 36028797018963966, 1, 576460752303423486, 1, 9223372036854775806, 1 (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..999 Eric Weisstein's World of Mathematics, Elementary Cellular Automaton FORMULA Conjectures from Colin Barker, Dec 28 2015 and Apr 15 2019: (Start) a(n) = (3*(-1)^n+2^(2*n+1)-(-1)^n*2^(2*n+1)-1)/2. a(n) = 17*a(n-2)-16*a(n-4) for n>3. G.f.: (1+6*x-16*x^2+24*x^3) / ((1-x)*(1+x)*(1-4*x)*(1+4*x)). (End) MATHEMATICA rule=15; 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. A266300. Sequence in context: A318107 A331557 A303675 * A183284 A224476 A123147 Adjacent sequences:  A266299 A266300 A266301 * A266303 A266304 A266305 KEYWORD nonn,easy AUTHOR Robert Price, Dec 26 2015 STATUS approved

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Last modified August 12 11:57 EDT 2020. Contains 336439 sequences. (Running on oeis4.)