A192557 a(n) = Sum_{k=0..n} Stirling2(n,k)*Stirling2(n+1,k+1)*k!.

1, 1, 5, 49, 749, 16201, 464645, 16911049, 756570029, 40608430681, 2565613446725, 187881747426649, 15746365790443469, 1494340848159224521, 159129983959516664645, 18866500386049170199849, 2473489038963025307690669, 356458089674089695970723321

Offset

0,3

Links

Table of n, a(n) for n=0..17.

Mathematica

Table[Sum[StirlingS2[n, k]StirlingS2[n+1, k+1]k!, {k, 0, n}], {n, 0, 100}]

Prog

(Maxima) makelist(sum(stirling2(n, k)*stirling2(n+1, k+1)*k!, k, 0, n), n, 0, 24);

Crossrefs

Sequence in context: A052750 A145088 A301386 * A357335 A290755 A062995

Adjacent sequences: A192554 A192555 A192556 * A192558 A192559 A192560

Keyword

nonn

Author

Emanuele Munarini, Jul 04 2011

Status

approved