A334511 Eventual period of a single cell in rule 9 cellular automaton in a cyclic universe of width n.

2, 2, 2, 2, 2, 9, 5, 12, 18, 5, 22, 12, 26, 14, 30, 16, 34, 18, 38, 20, 42, 22, 46, 24, 50, 26, 54, 28, 58, 30, 62, 32, 66, 34, 70, 36, 74, 38, 78, 40, 82, 42, 86, 44, 90, 46, 94, 48, 98, 50, 102, 52, 106, 54, 110, 56, 114, 58, 118, 60, 122, 62, 126, 64, 130

Offset

1,1

Comments

Bradley Klee computed a(1)-a(10).

References

Bradley Klee, Posting to Math Fun Mailing List, Apr 26 2020

Links

Table of n, a(n) for n=1..65.

Formula

Conjectures from Colin Barker, May 09 2020: (Start)

G.f.: x*(2 + 2*x - 2*x^2 - 2*x^3 + 7*x^5 + 3*x^6 - 4*x^7 + 10*x^8 - 10*x^9 - 9*x^10 + 14*x^11 - 5*x^13) / ((1 - x)^2*(1 + x)^2).

a(n) = 2*a(n-2) - a(n-4) for n>14.

(End)

Conjecture: a(n) = (3 - (-1)^n)*n/2 for n > 10. - Stefano Spezia, Sep 11 2021

Crossrefs

Cf. A180001, A334496, A334499-A334515.

Sequence in context: A010671 A339164 A323443 * A291944 A253633 A216844

Adjacent sequences: A334508 A334509 A334510 * A334512 A334513 A334514

Keyword

nonn

Author

N. J. A. Sloane, May 05 2020

Extensions

More terms from Jinyuan Wang, May 09 2020

Status

approved