A246248 - OEIS

%I #12 Aug 26 2014 17:01:32

%S 11259,443718,12450834,297195804,6589314360,141014406600,

%T 2982538767870,63210091744620,1354523537530620,29518995185712180,

%U 656767731733672680,14956075051814966040,349170616179434073825,8366057002343951876610,205839505389444095064510

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

%H Alois P. Heinz, <a href="/A246248/b246248.txt">Table of n, a(n) for n = 10..160</a>

%F a(n) ~  c * (3*sqrt(3)/(2*Pi))^n * n! * n^3, where c = 0.01095971939528021798... = c0 * (c0-1)^3 / (3^3 * 3!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - _Vaclav Kotesovec_, Aug 26 2014

%Y Column k=3 of A242819.

%K nonn

%O 10,1

%A _Alois P. Heinz_, Aug 20 2014