A349288 Number of permutations p of {1,2,...,n} such that p(k) divides p(k+1) + p(k+2) for all k in {1,2,...,n-2}.

1, 2, 6, 6, 15, 14, 9, 28, 16, 37, 51, 13, 34, 44, 5, 20, 24, 15, 45, 52, 2, 8, 34, 21, 15, 13, 1, 2, 1, 0, 0, 0, 0, 1, 0, 0, 3, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,2

Links

Table of n, a(n) for n=1..77.

Max Alekseyev, List of suitable permutations for each n=1..60

V. S. Guba, Problem of the day-13, 2021. (in Russian)

Crossrefs

Cf. A349294 (indices of nonzero terms).

Sequence in context: A251548 A316785 A056136 * A098571 A194120 A161503

Adjacent sequences: A349285 A349286 A349287 * A349289 A349290 A349291

Keyword

nonn

Author

Max Alekseyev, Nov 13 2021

Extensions

a(61)-a(64) from Rene, added by Max Alekseyev, Jun 10 2022

a(65)-a(77) from Oleg Tarakanov, Sep 27 2024

Status

approved