A055968 Product_{i=1..n} (i-1)!*(i+2*n-1)!/(i+n-1)!.

1, 2, 240, 16934400, 2433481408512000, 1702585913798082900787200000, 11371604489970305906683404111524659200000000, 1255487625657168098911809977092685237691748290920448000000000000

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Maple

A055968 := proc(n) local i; mul( (i-1)!*(i+2*n-1)!/(i+n-1)!, i=1..n); end;

Crossrefs

Sequence in context: A024348 A006523 A294319 * A068838 A074256 A146312

Adjacent sequences: A055965 A055966 A055967 * A055969 A055970 A055971

Keyword

nonn

Author

N. J. A. Sloane, Jul 22 2000

Status

approved