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

Author

R. J. Mathar, Oct 27 2014

Keywords

• nonn
• more

Crossrefs

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

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