Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #14 Mar 03 2016 11:50:35
%S 2,28,704,26800,1404416,94890112,7887853568,779773444864,
%T 89407927009280,11666949886007296,1707352344419336192,
%U 276938622991133237248,49316570352062326636544,9565558797749164794511360,2007400581177856844629016576,453192947995950052758954115072
%N INVERT transform of A089835.
%H Alois P. Heinz, <a href="/A089836/b089836.txt">Table of n, a(n) for n = 1..150</a>
%F a(n) ~ 16^n * n! / (Pi*n^2). - _Vaclav Kotesovec_, Sep 05 2014
%p INVERT(A089835); INVERT([seq(A000108(n)*A000108(n)*(n+1)!,n=1..9)]);
%p a:= proc(n) option remember; local i; `if`(n<1, 1, add(a(n-i) *(2*i)!^2 /i!^3 /(i+1), i=1..n)) end: seq(a(n), n=1..20); # _Alois P. Heinz_, Apr 01 2009
%t a[n_] := a[n] = If[n < 1, 1, Sum[a[n - i] *(2 i)!^2 /i!^3 /(i + 1), {i, 1, n}]]; Array[a, 20] (* _Jean-François Alcover_, Mar 03 2016, adapted from Maple *)
%K nonn
%O 1,1
%A _Antti Karttunen_, Dec 05 2003
%E More terms from _Alois P. Heinz_, Apr 01 2009