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
Keywords
Examples
a(3) = 25 = sum of row 3 terms of triangle A131429: (5 + 5 + 6 + 9).
Links
- Andrew Howroyd, Table of n, a(n) for n = 0..200
Programs
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PARI
a(n)={binomial(2*n,n) - n - 1 + sum(k=0, n, binomial(2*k,k)/(k+1))} \\ Andrew Howroyd, Aug 28 2018
Formula
a(n) = binomial(2*n, n) - (n+1) + Sum_{k=0..n} binomial(2*k, k)/(k+1). - Andrew Howroyd, Aug 28 2018
Extensions
Terms a(10) and beyond from Andrew Howroyd, Aug 28 2018