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A267775 Binary representation of the n-th iteration of the "Rule 207" elementary cellular automaton starting with a single ON (black) cell. 1
1, 110, 11101, 1111011, 111110111, 11111101111, 1111111011111, 111111110111111, 11111111101111111, 1111111111011111111, 111111111110111111111, 11111111111101111111111, 1111111111111011111111111, 111111111111110111111111111, 11111111111111101111111111111 (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 sequences related to cellular automata

Index to Elementary Cellular Automata

FORMULA

Conjectures from Colin Barker, Jan 20 2016 and Apr 20 2019: (Start)

a(n) = 111*a(n-1)-1110*a(n-2)+1000*a(n-3) for n>3.

G.f.: (1-x+x^2-100*x^3) / ((1-x)*(1-10*x)*(1-100*x)).

(End)

MATHEMATICA

rule=207; 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. A267773.

Sequence in context: A211979 A135650 A193240 * A267867 A267889 A285696

Adjacent sequences:  A267772 A267773 A267774 * A267776 A267777 A267778

KEYWORD

nonn,easy

AUTHOR

Robert Price, Jan 20 2016

STATUS

approved

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Last modified December 4 14:42 EST 2020. Contains 338924 sequences. (Running on oeis4.)