A246250 Number of permutations of [n] with exactly five occurrences of the consecutive step pattern up, down, down.

1620265923, 142031290158, 8039798211078, 366995453376294, 14827018289073804, 555488440936519572, 19848769453749875607, 688735406876831016606, 23495176763112174568146, 794853120296757717355104, 26836227616917587293450368, 908479209956520414451380624

Offset

16,1

Links

Alois P. Heinz, Table of n, a(n) for n = 16..160

Formula

a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^5, where c = 0.00005687732922585807984... = c0 * (c0-1)^5 / (3^5 * 5!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - Vaclav Kotesovec, Aug 26 2014

Crossrefs

Column k=5 of A242819.

Sequence in context: A166383 A227444 A329463 * A373001 A126432 A186175

Adjacent sequences: A246247 A246248 A246249 * A246251 A246252 A246253

Keyword

nonn

Author

Alois P. Heinz, Aug 20 2014

Status

approved