A267043 - OEIS

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A267043

Middle column of the "Rule 91" elementary cellular automaton starting with a single ON (black) cell.

1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0

(list; graph; refs; listen; history; text; internal format)

OFFSET

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

Conjecture: a(n) = A266070(n-1), n>1. - R. J. Mathar, Jan 17 2016

MATHEMATICA

rule=91; 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[catri[[k]][[k]], {k, 1, rows}] (* Keep only middle cell from each row *)

CROSSREFS

Cf. A267015.

Sequence in context: A141737 A285301 A089011 * A266444 A267679 A267868

Adjacent sequences: A267040 A267041 A267042 * A267044 A267045 A267046

KEYWORD

nonn,easy

AUTHOR

Robert Price, Jan 09 2016

STATUS

approved