A246250 - OEIS

%I #10 Aug 26 2014 17:02:55

%S 1620265923,142031290158,8039798211078,366995453376294,

%T 14827018289073804,555488440936519572,19848769453749875607,

%U 688735406876831016606,23495176763112174568146,794853120296757717355104,26836227616917587293450368,908479209956520414451380624

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

%H Alois P. Heinz, <a href="/A246250/b246250.txt">Table of n, a(n) for n = 16..160</a>

%F 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

%Y Column k=5 of A242819.

%K nonn

%O 16,1

%A _Alois P. Heinz_, Aug 20 2014