OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
FORMULA
a(n) = Sum_{k=1..n} (2k-1)! binomial(n,k)^2.
MAPLE
a:= n-> add((2*k-1)!*binomial(n, k)^2, k=1..n):
seq(a(n), n=0..20); # Alois P. Heinz, Jun 14 2015
PROG
(PARI) a(n) = sum(k=1, n, (2*k-1)! * binomial(n, k)^2); \\ Michel Marcus, Aug 14 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Lukas Brantner (dlbb2(AT)cam.ac.uk), Jul 17 2010
EXTENSIONS
More terms from Michel Marcus, Aug 14 2013
STATUS
approved