A246253 Number of permutations of [n] with exactly eight occurrences of the consecutive step pattern up, down, down.

4736552519729393091, 925712659777722254622, 108450427756505074280046, 9790367872313042801164557, 752566904329661335915465770, 51895294413875186427307822050, 3313685917841456847408819072255, 200074814234955942882986408262750, 11591748407639299505418556743604770

Offset

25,1

Links

Alois P. Heinz, Table of n, a(n) for n = 25..160

Formula

a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^8, where c = 0.00000000566049683079281633... = c0 * (c0-1)^8 / (3^8 * 8!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - Vaclav Kotesovec, Aug 26 2014

Crossrefs

Column k=8 of A242819.

Sequence in context: A288289 A104839 A219346 * A003812 A003805 A115530

Adjacent sequences: A246250 A246251 A246252 * A246254 A246255 A246256

Keyword

nonn

Author

Alois P. Heinz, Aug 20 2014

Status

approved