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A267449
Binary representation of the n-th iteration of the "Rule 131" elementary cellular automaton starting with a single ON (black) cell.
1
1, 100, 10010, 1001000, 100100110, 10010010000, 1001001001110, 100100100101000, 10010010010000110, 1001001001001110000, 100100100100101001110, 10010010010010000101000, 1001001001001001110000110, 100100100100100101001110000, 10010010010010010000101001110
OFFSET
0,2
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
Empirical g.f.: (1+10*x^2-1000*x^3+109*x^4-11000*x^5+1100*x^6-119000*x^7+900000*x^8) / ((1-x)*(1+x)*(1-10*x)*(1-100*x)*(1+x^2)*(1+10*x+100*x^2)). - Colin Barker, Jan 15 2016 and Apr 19 2019
MATHEMATICA
rule=131; 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 *)
CROSSREFS
Cf. A267418.
Sequence in context: A098608 A045799 A096885 * A266752 A267523 A027576
KEYWORD
nonn
AUTHOR
Robert Price, Jan 15 2016
STATUS
approved