A089836 INVERT transform of A089835.

2, 28, 704, 26800, 1404416, 94890112, 7887853568, 779773444864, 89407927009280, 11666949886007296, 1707352344419336192, 276938622991133237248, 49316570352062326636544, 9565558797749164794511360, 2007400581177856844629016576, 453192947995950052758954115072

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..150

Formula

a(n) ~ 16^n * n! / (Pi*n^2). - Vaclav Kotesovec, Sep 05 2014

Maple

INVERT(A089835); INVERT([seq(A000108(n)*A000108(n)*(n+1)!, n=1..9)]);
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

Mathematica

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 *)

Crossrefs

Sequence in context: A246483 A151332 A098631 * A372164 A372165 A090249

Adjacent sequences: A089833 A089834 A089835 * A089837 A089838 A089839

Keyword

nonn

Author

Antti Karttunen, Dec 05 2003

Extensions

More terms from Alois P. Heinz, Apr 01 2009

Status

approved