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A267846
Binary representation of the n-th iteration of the "Rule 227" elementary cellular automaton starting with a single ON (black) cell.
1
1, 100, 11010, 1111010, 111111010, 11111111010, 1111111111010, 111111111111010, 11111111111111010, 1111111111111111010, 111111111111111111010, 11111111111111111111010, 1111111111111111111111010, 111111111111111111111111010, 11111111111111111111111111010
OFFSET
0,2
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
FORMULA
Conjectures from Colin Barker, Jan 21 2016: (Start)
a(n) = 101*a(n-1)-100*a(n-2) for n>3.
G.f.: (1-x+1010*x^2+9000*x^3) / ((1-x)*(1-100*x)).
(End)
MATHEMATICA
rule=227; 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. A267845.
Sequence in context: A163663 A272681 A267674 * A267684 A267885 A307810
KEYWORD
nonn
AUTHOR
Robert Price, Jan 21 2016
STATUS
approved