A098628 Consider the family of multigraphs enriched by the species of parts. Sequence gives number of those multigraphs with n labeled edges.

1, 2, 12, 128, 2224, 56000, 1880832, 79985792, 4161468928, 258415579648, 18793653411840, 1576791247634432, 150745211441983488, 16253127712884269056, 1959064946185017851904, 262002352633857351942144, 38624060984664180255621120, 6240304185636529522872025088

Offset

0,2

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]

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 A000079. - Andrew Howroyd, Jan 12 2021

Prog

(PARI) \\ R(n) is A000079 as e.g.f.; EnrichedGnSeq defined in A098620.
R(n)={exp(2*x + O(x*x^n))}
EnrichedGnSeq(R(20)) \\ Andrew Howroyd, Jan 12 2021

Crossrefs

Cf. A000079, A014500, A098620, A098629, A098630, A098631.

Sequence in context: A097629 A259267 A014235 * A123553 A354493 A079199

Adjacent sequences: A098625 A098626 A098627 * A098629 A098630 A098631

Keyword

nonn

Author

N. J. A. Sloane, Oct 26 2004

Extensions

Terms a(11) and beyond from Andrew Howroyd, Jan 12 2021

Status

approved