1,2
Table of n, a(n) for n=1..6.
Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
a(n)=sum((-720)^i*binomial(n,i)*(6*n-6*i)!,i=0..n).
a(5)=265250626231132937174895820800000
a:=n->sum((-720)^i*binomial(n, i)*(6*n-6*i)!, i=0..n).
Sequence in context: A260524 A091677 A147717 * A072232 A011523 A172535
Adjacent sequences: A127885 A127886 A127887 * A127889 A127890 A127891
nonn
Milan Janjic, Apr 09 2007
approved