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
Keywords
Examples
a(4) = 18 = sum of row 4 terms of triangle A132789: (1 + 8 + 8 + 1).
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..200
Crossrefs
Cf. A132789.
Programs
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PARI
a(n)=sum(k=1, n, binomial(n-1,k-1)*(1 + binomial(n,k-1)/k) - 1); \\ Andrew Howroyd, Sep 01 2018
Formula
a(n) = Sum_{k=1..n} binomial(n-1,k-1)*(1 + binomial(n,k-1)/k) - 1. - Andrew Howroyd, Sep 01 2018
Extensions
Terms a(11) and beyond from Andrew Howroyd, Sep 01 2018