A246252 - OEIS

%I #10 Aug 26 2014 17:04:45

%S 2172534146099019,336291324862551606,31816048233798681066,

%T 2348418329934108057072,149140942861163014893024,

%U 8573289075750149662810032,460018114299281721089786796,23509721961960146267578379640,1160583084129910496820714859320

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

%H Alois P. Heinz, <a href="/A246252/b246252.txt">Table of n, a(n) for n = 22..160</a>

%F a(n) ~  c * (3*sqrt(3)/(2*Pi))^n * n! * n^7, where c = 0.0000001405593242634352116... = c0 * (c0-1)^7 / (3^7 * 7!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - _Vaclav Kotesovec_, Aug 26 2014

%Y Column k=7 of A242819.

%K nonn

%O 22,1

%A _Alois P. Heinz_, Aug 20 2014