A131430 Row sums of triangle A131429.

1, 2, 7, 25, 88, 311, 1114, 4050, 14917, 55528, 208459, 787920, 2994655, 11433998, 43824437, 168520201, 649840740, 2512011359, 9731179138, 37768570827, 146833956266, 571711568905, 2229035221824, 8701426599353, 34005503702176, 133030452858279, 520905732440782

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200

Formula

a(n) = binomial(2*n, n) - (n+1) + Sum_{k=0..n} binomial(2*k, k)/(k+1). - Andrew Howroyd, Aug 28 2018

Example

a(3) = 25 = sum of row 3 terms of triangle A131429: (5 + 5 + 6 + 9).

Prog

(PARI) a(n)={binomial(2*n, n) - n - 1 + sum(k=0, n, binomial(2*k, k)/(k+1))} \\ Andrew Howroyd, Aug 28 2018

Crossrefs

Cf. A000108, A131427, A131428, A131429.

Sequence in context: A370022 A289598 A030017 * A007484 A070859 A048576

Adjacent sequences: A131427 A131428 A131429 * A131431 A131432 A131433

Keyword

nonn

Author

Gary W. Adamson, Jul 10 2007

Extensions

Terms a(10) and beyond from Andrew Howroyd, Aug 28 2018

Status

approved