A132790 Row sums of triangle A132789.

1, 2, 6, 18, 53, 158, 486, 1550, 5109, 17298, 59799, 210048, 746983, 2682618, 9711214, 35390422, 129710309, 477769754, 1767525315, 6564644688, 24467315575, 91484660770, 343063807931, 1289912535908, 4861963178643, 18367386626558, 69533618024841, 263748085968060

Offset

1,2

Links

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

Formula

a(n) = Sum_{k=1..n} binomial(n-1,k-1)*(1 + binomial(n,k-1)/k) - 1. - Andrew Howroyd, Sep 01 2018

Example

a(4) = 18 = sum of row 4 terms of triangle A132789: (1 + 8 + 8 + 1).

Prog

(PARI) a(n)=sum(k=1, n, binomial(n-1, k-1)*(1 + binomial(n, k-1)/k) - 1); \\ Andrew Howroyd, Sep 01 2018

Crossrefs

Cf. A132789.

Sequence in context: A252822 A094864 A120010 * A358417 A372899 A214799

Adjacent sequences: A132787 A132788 A132789 * A132791 A132792 A132793

Keyword

nonn

Author

Gary W. Adamson, Aug 30 2007

Extensions

Terms a(11) and beyond from Andrew Howroyd, Sep 01 2018

Status

approved