A099708 Consider the family of multigraphs enriched by the species of endofunctions. Sequence gives number of those multigraphs with n labeled edges.

1, 1, 6, 60, 854, 16029, 378871, 10926690, 375538541, 15097900582, 699359781567, 36859422340308, 2187121403805853, 144804645827958839, 10615679263174481480, 856040905847508506792, 75495130803739278866508, 7244702305184037575057831, 753093536414613689614872227

Offset: 0

Author

N. J. A. Sloane, Oct 26 2004

Keywords

• nonn

References

• G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004.

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..100
• G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004. [Cached copy, with permission]

Crossrefs

Cf. A000312, A014500, A098620, A099709, A099710, A099711.

Programs

PARI

\\ R(n) is A000312 as e.g.f.; EnrichedGnSeq defined in A098620.
R(n)={1/(1 + lambertw(-x + O(x*x^n)))}
EnrichedGnSeq(R(20)) \\ Andrew Howroyd, Jan 12 2021

Formula

E.g.f.: B(R(x)) where B(x) is the e.g.f. of A014500 and 1 + R(x) is the e.g.f. of A000312. - Andrew Howroyd, Jan 12 2021

Extensions

Terms a(12) and beyond from Andrew Howroyd, Jan 12 2021