A103719 Column m=2 sequence of triangle A103718(n,m), n >= 0 (without leading zeros).

1, 7, 45, 310, 2359, 19901, 185408, 1896380, 21163076, 256176052, 3345574440, 46910470152, 703146058224, 11222813318544, 190069993713024, 3404916420352128, 64333503601542144, 1278725806081645056

Offset

0,2

Links

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

Formula

a(n) = |S1(n+3, 3)| + |S1(n+3, 4)| = |S1(n+4, 4)| - (n+2)*|S1(n+3, 4)|, with S1(n, m):= A048994(n, m), n >= m >= 0 (Stirling1 triangle).

Crossrefs

Cf. A048994, A103718.

Sequence in context: A280597 A301319 A143835 * A134437 A018927 A001266

Adjacent sequences: A103716 A103717 A103718 * A103720 A103721 A103722

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 24 2005

Status

approved