OFFSET
1,3
LINKS
FORMULA
a(n) = Sum_{k=0..[ n/2 ]} k^2*n!/((n-2*k)!*2^k*k!).
PROG
(PARI) a(n) = sum(k=0, n\2 , k^2*n!/((n-2*k)!*2^k*k!)); \\ Michel Marcus, Aug 10 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Rajan Murthy, Nov 30 2010
EXTENSIONS
More terms from Michel Marcus, Aug 10 2013
STATUS
approved