cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A099716 Consider the family of multigraphs enriched by the species of trees. Sequence gives number of those multigraphs with n labeled edges.

Original entry on oeis.org

1, 1, 3, 18, 170, 2244, 38686, 834594, 21874433, 681399298, 24797467947, 1039645748808, 49632586028650, 2671404673776080, 160726892084432840, 10729582290405547592, 789572236551678855603, 63682341168165082629698, 5600777517339868668401105
Offset: 0

Views

Author

N. J. A. Sloane, Oct 26 2004

Keywords

References

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

Crossrefs

Programs

  • PARI
    \\ R(n) is A000272 as e.g.f.; EnrichedGnSeq defined in A098620.
    R(n)={my(w=lambertw(-x + O(x*x^n))); 1 - w - w^2/2}
    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 A000272. - Andrew Howroyd, Jan 12 2021

Extensions

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

A099718 Consider the family of directed multigraphs enriched by the species of trees. Sequence gives number of those multigraphs with n labeled loops and edges.

Original entry on oeis.org

1, 2, 15, 207, 4274, 120698, 4408714, 200482089, 11035845002, 719691942986, 54661283926338, 4768412660292713, 472309503983879356, 52604316569196875434, 6533611563916740388476, 898472724512273277951811, 135941600045496082012663932, 22505828691354514668620263242
Offset: 0

Views

Author

N. J. A. Sloane, Oct 26 2004

Keywords

References

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

Crossrefs

Programs

  • PARI
    \\ R(n) is A000272 as e.g.f.; EnrichedGdlSeq defined in A098622.
    R(n)={my(w=lambertw(-x + O(x*x^n))); 1 - w - w^2/2}
    EnrichedGdlSeq(R(20)) \\ Andrew Howroyd, Jan 12 2021

Formula

E.g.f.: B(R(x)) where B(x) is the e.g.f. of A014507 and 1 + R(x) is the e.g.f. of A000272. - Andrew Howroyd, Jan 12 2021

Extensions

Terms a(12) and beyond from Andrew Howroyd, Jan 12 2021
Showing 1-2 of 2 results.