A293914 - OEIS

%I #9 Oct 25 2017 18:08:00

%S 1,2,10,69,616,6740,87291,1305710,22149226,420113979,8810083360,

%T 202397302184,5054993327385,136370982998354,3951907646699026,

%U 122432049983991285,4038019273764782056,141261207847788852620,5224370049771189478371,203670050053447478737214

%N Number of linear chord diagrams having n chords and minimal chord length one.

%H Alois P. Heinz, <a href="/A293914/b293914.txt">Table of n, a(n) for n = 1..404</a>

%F a(n) ~ (1 - exp(-1)) * 2^(n + 1/2) * n^n / exp(n). - _Vaclav Kotesovec_, Oct 25 2017

%p a:= proc(n) option remember; `if`(n<3, n, (4*n-6)*

%p       a(n-1)-2*(2*n^2-8*n+7)*a(n-2)-(2*n-5)*a(n-3))

%p     end:

%p seq(a(n), n=1..25);

%Y Column k=1 of A293881.

%K nonn

%O 1,2

%A _Alois P. Heinz_, Oct 19 2017