A094602 Total number of edges in all connected unlabeled graphs on n nodes.

0, 1, 5, 25, 130, 951, 9552, 160220, 4756703, 264964172, 27746801125, 5419696866001, 1964101824992259, 1319988856541150115, 1648566523004692022634, 3838409698542815296758222, 16719797018733808721401666187, 136732968429033400292302529059213

Offset: 1

Author

Vladeta Jovovic, Jun 06 2004

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..50

Crossrefs

Cf. A046751, A054923, A054924, A086314, A095351.

Programs

PARI

\\ See A054923 for G, InvEulerMT.
a(n)={subst(deriv(InvEulerMT(vector(n, k, G(k,y)))[n]), y, 1)} \\ Andrew Howroyd, Feb 01 2020

Formula

a(n) = Sum_{k=1..binomial(n,2)} k*A054924(n, k). - Andrew Howroyd, Feb 01 2020

Extensions

Terms a(17) and beyond from Andrew Howroyd, Feb 01 2020