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A267776 Triangle read by rows giving successive states of cellular automaton generated by "Rule 209" initiated with a single ON (black) cell. 2
1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0

COMMENTS

Row n has length 2n+1.

This sequence is also generated by Rule 241.

REFERENCES

S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

LINKS

Robert Price, Table of n, a(n) for n = 0..10000

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

EXAMPLE

The first ten rows:

                  1

                0 0 1

              1 1 0 0 1

            1 1 1 1 0 0 1

          1 1 1 1 1 1 0 0 1

        1 1 1 1 1 1 1 1 0 0 1

      1 1 1 1 1 1 1 1 1 1 0 0 1

    1 1 1 1 1 1 1 1 1 1 1 1 0 0 1

  1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1

MATHEMATICA

rule=209; 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 *) Flatten[catri] (* Triangle Representation of CA *)

CROSSREFS

Sequence in context: A004609 A287674 A071001 * A072792 A254113 A267037

Adjacent sequences:  A267773 A267774 A267775 * A267777 A267778 A267779

KEYWORD

nonn,tabf,easy

AUTHOR

Robert Price, Jan 20 2016

STATUS

approved

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Last modified November 24 07:53 EST 2020. Contains 338607 sequences. (Running on oeis4.)