A192568 a(n) = sum(Stirling2(n,k)*Stirling2(n+1,k+1)*Stirling2(n+2,k+2),k=0..n).

1, 1, 19, 356, 13626, 712482, 51437310, 5021800835, 618616762763, 95445366568311, 18045402520903033, 4089264784742659744, 1098689143687870325930, 345713999063910185516303, 125935810020098258689919235, 52660666992259419412862687142

Offset

0,3

Links

Table of n, a(n) for n=0..15.

Mathematica

Table[Sum[StirlingS2[n, k]StirlingS2[n+1, k+1]StirlingS2[n+2, k+2], {k, 0, n}], {n, 0, 100}]

Prog

(Maxima) makelist(sum(stirling2(n, k)*stirling2(n+1, k+1)*stirling2(n+2, k+2), k, 0, n), n, 0, 24);

Crossrefs

Cf. A008275, A008277.

Sequence in context: A170738 A218721 A282030 * A171324 A078368 A332798

Adjacent sequences: A192565 A192566 A192567 * A192569 A192570 A192571

Keyword

nonn

Author

Emanuele Munarini, Jul 04 2011

Status

approved