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A267207
Decimal representation of the n-th iteration of the "Rule 109" elementary cellular automaton starting with a single ON (black) cell.
1
1, 2, 31, 34, 471, 762, 7967, 8866, 120791, 194810, 2037023, 2277026, 30918615, 49850618, 521532703, 582893218, 7914997719, 12762196218, 133512164639, 149219327650, 2026242918359, 3267120572666, 34179103454495, 38200175902370, 518718173824983
OFFSET
0,2
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
Empirical g.f.: (1 +4*x +39*x^2 +104*x^3 +406*x^4 +812*x^5 +1352*x^6 +1120*x^7 +256*x^8 -3584*x^10) / ((1 -x)*(1 +x)*(1 -4*x)*(1 +4*x)*(1 +x^2)*(1 +2*x +4*x^2)*(1 +16*x^2)). - Colin Barker, Jan 13 2016 and Apr 19 2019
MATHEMATICA
rule=109; 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. A243566.
Sequence in context: A053234 A020896 A042153 * A102630 A264783 A215031
KEYWORD
nonn,easy
AUTHOR
Robert Price, Jan 11 2016
STATUS
approved