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.

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A361254 Number of n-regular graphs on 2*n labeled nodes.

Original entry on oeis.org

1, 1, 3, 70, 19355, 66462606, 2977635137862, 1803595358964773088, 15138592322753242235338875, 1793196665025885172290508971592750, 3040059281615704147007085764679679740691838, 74597015246986083384362428357508730776063716190667288, 26737694395324301026230134763403079891362936970900741153038680278
Offset: 0

Views

Author

Atabey Kaygun, Mar 06 2023

Keywords

Comments

These graphs share the same degree sequence as the complete bipartite graphs K(n,n).

Links

Crossrefs

Cf. A001223, A059441, A339987, A360437.

Programs

  • PARI
    \\ See Links in A295193 for GraphsByDegreeSeq.
a(n)={if(n==0, 1, vecsum(GraphsByDegreeSeq(2*n, n, (p, r)->valuation(p,x) >= n-r)[, 2])) } \\ Andrew Howroyd, Mar 06 2023

Formula

a(n) = A059441(2*n, n).

Extensions

a(11)-a(12) from Andrew Howroyd, Mar 06 2023

A376071 Number of (non-null) regular subgraphs of a complete graph having n labeled vertices.

Original entry on oeis.org

1, 4, 11, 32, 99, 452, 2829, 59728, 1548859, 168927280, 12165067397, 7074423251656, 2294426405588381, 4218009215702408336, 3810376434461485027083, 35102248193591661086986784, 156873334244228518638713218203, 4144940994226400702145709978496296
Offset: 1

Views

Author

Maharshee K. Shah, Sep 08 2024

Keywords

Crossrefs

Cf. A295193.

Formula

a(n) = Sum_{k=1..n} binomial(n,k)*A295193(k). - Andrew Howroyd, Sep 08 2024

Extensions

a(9) onwards from Andrew Howroyd, Sep 08 2024
Previous Showing 31-32 of 32 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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