OFFSET
1,2
COMMENTS
Essentially the same as A074319. [From R. J. Mathar, Sep 08 2008]
EXAMPLE
a(1)=2!=2, a(2)=3!*4!=144, a(3)=4!*5!*6!, a(4)=5!*6!*7!*8!.
PROG
(PARI) a(n)=prod(i=n+1, 2*n, i!)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Mar 29 2004
EXTENSIONS
Corrected and extended by Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 29 2004
STATUS
approved