A246254 Number of permutations of [n] with exactly nine occurrences of the consecutive step pattern up, down, down.

14708695606607601165843, 3541988733308075285027550, 503174667865819228904767230, 54504030281627517895808563770, 4983196403246326034913729334260, 405629500925435775383214597193020, 30367312487678851547450846684842845, 2136522202012396295876641497958908090

Offset

28,1

Links

Alois P. Heinz, Table of n, a(n) for n = 28..160

Formula

a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^9, where c = 0.0000000002026268159682390665... = c0 * (c0-1)^9 / (3^9 * 9!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - Vaclav Kotesovec, Aug 26 2014

Crossrefs

Column k=9 of A242819.

Sequence in context: A095440 A326414 A162033 * A238360 A304373 A316155

Adjacent sequences: A246251 A246252 A246253 * A246255 A246256 A246257

Keyword

nonn

Author

Alois P. Heinz, Aug 20 2014

Status

approved