

A267780


Decimal representation of the nth iteration of the "Rule 211" elementary cellular automaton starting with a single ON (black) cell.


1



1, 5, 25, 125, 505, 2045, 8185, 32765, 131065, 524285, 2097145, 8388605, 33554425, 134217725, 536870905, 2147483645, 8589934585, 34359738365, 137438953465, 549755813885, 2199023255545, 8796093022205, 35184372088825, 140737488355325, 562949953421305
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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) = 4*a(n1)+a(n2)4*a(n3) for n>3.
G.f.: (1+x+4*x^2+24*x^3) / ((1x)*(1+x)*(14*x)).
(End)


MATHEMATICA

rule=211; rows=20; ca=CellularAutomaton[rule, {{1}, 0}, rows1, {All, All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]], {rowsk+1, rows+k1}], {k, 1, rows}]; (* Truncated list of each row *) Table[FromDigits[catri[[k]], 2], {k, 1, rows}] (* Decimal Representation of Rows *)


CROSSREFS

Cf. A267778.
Sequence in context: A061974 A015950 A337950 * A228736 A126642 A269615
Adjacent sequences: A267777 A267778 A267779 * A267781 A267782 A267783


KEYWORD

nonn,easy


AUTHOR

Robert Price, Jan 20 2016


STATUS

approved



