A267537 Middle column of the "Rule 143" elementary cellular automaton starting with a single ON (black) cell.

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

Offset

0

Comments

Decimal expansion of 9901/90000. - Elmo R. Oliveira, Sep 24 2025

Links

Robert Price, Table of n, a(n) for n = 0..1000

Eric Weisstein's World of Mathematics, Elementary Cellular Automaton.

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

Index entries for sequences related to cellular automata.

Index to Elementary Cellular Automata.

Index entries for linear recurrences with constant coefficients, signature (1).

Formula

a(n)=1 for n>=4. - R. J. Mathar, Aug 07 2025

From Elmo R. Oliveira, Sep 24 2025: (Start)

G.f.: 1 + x + x^4/(1-x).

E.g.f.: exp(x) - x^2/2 - x^3/6. (End)

Mathematica

rule=143; 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. A267533, A267800, A267538, A267539.

Sequence in context: A134668 A309970 A039963 * A329670 A183919 A355449

Adjacent sequences: A267534 A267535 A267536 * A267538 A267539 A267540

Keyword

nonn,easy

Author

Robert Price, Jan 16 2016

Status

approved