A137856 Row sums of triangle A137855.

1, 2, 4, 8, 17, 39, 97, 261, 756, 2343, 7722, 26917, 98789, 380360, 1531698, 6434385, 28130890, 127729730, 601196428, 2928369917, 14738842361, 76547694741, 409718539681, 2257459567236, 12789959138943, 74439150889080, 444647798089245, 2723583835351855

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Formula

a(n) = Sum_{k=1..n} Sum_{j=1..n-k+1} Stirling2(k, j). - Andrew Howroyd, Aug 09 2018

Example

a(5) = 17 = sum of row 5 terms of triangle A137855: (1 + 2 + 5 + 8 + 1).

Prog

(PARI) a(n)={sum(k=1, n, sum(j=1, n-k+1, stirling(k, j, 2)))} \\ Andrew Howroyd, Aug 09 2018

Crossrefs

Cf. A137855.

Partial sums of A024427.

Sequence in context: A054199 A054197 A287776 * A304970 A090375 A210540

Adjacent sequences: A137853 A137854 A137855 * A137857 A137858 A137859

Keyword

nonn

Author

Gary W. Adamson, Feb 18 2008

Extensions

Terms a(12) and beyond from Andrew Howroyd, Aug 09 2018

Status

approved