OFFSET
1,1
COMMENTS
p divides a((p-1)/2) for prime p>2.
FORMULA
a(n) = Sum[Sum[(2n+i+j)!/(n+i)!/(n+j)!,{i,1,n}],{j,1,n}].
MATHEMATICA
Table[Sum[Sum[(2n+i+j)!/(n+i)!/(n+j)!, {i, 1, n}], {j, 1, n}], {n, 1, 20}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Jul 04 2006
STATUS
approved