A214669 a(n) = Sum_{k=1..n*(n+1)/2} k * A214670(n,k).

1, -4, 36, -720, 29264, -2370368, 379341376, -119616350464, 74306729686272, -91021121260127232, 220137897341768508416, -1052620193410626774192128, 9963741205378506824566067200, -186912918064963001770860269879296, 6955904583765468148520677987319955456

Offset

1,2

Links

Table of n, a(n) for n=1..15.

Prog

 (PARI) {a(n)=local(A214670=x*y); A214670=sum(m=1, n, -x^m*prod(j=1, m, (1-(1+y)^j)/(1-x*(1+y)^j))+x*O(x^n)); polcoeff(subst(deriv(A214670, y), y, 1), n, x)}
for(n=1, 25, print1(a(n), ", "))

Crossrefs

Cf. A214670.

Sequence in context: A322782 A145565 A360903 * A126152 A353996 A009446

Adjacent sequences: A214666 A214667 A214668 * A214670 A214671 A214672

Keyword

sign

Author

Paul D. Hanna, Jul 25 2012

Status

approved