A249393 The number of down-up permutations of [n] where adjacent elements differ by at least 6.

1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 64, 4352, 103680, 2644488, 48052224, 922764744, 15466088448, 271484691944, 4512300607488, 78169637107873, 1332149989277696, 23596090882390538

Offset

0,14

Links

Table of n, a(n) for n=0..24.

Crossrefs

Cf. A245377 (stride >=2), A249390, A249391, A249392, A179959 (non-alternating).

Sequence in context: A203438 A264345 A099369 * A208708 A189957 A146496

Adjacent sequences: A249390 A249391 A249392 * A249394 A249395 A249396

Keyword

nonn,more

Author

R. J. Mathar, Oct 27 2014

Extensions

a(19)-a(20) from Alois P. Heinz, Oct 27 2014

a(21) from Alois P. Heinz, Oct 29 2014

a(22)-a(24) from Max Alekseyev, Mar 09 2024

Status

approved