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.

Previous Showing 11-15 of 15 results.

A129425 Number of isomorphism classes of connected 8-regular loopless multigraphs of order n.

Original entry on oeis.org

0, 1, 1, 9, 36, 571, 12465, 543116, 35241608, 3230417239, 397514307014, 63830872225605, 13080448625309965, 3358687593761378470, 1063838242661288090062, 410057057694777406364151, 190064879184725871853627854, 104825763290631293396894238206
Offset: 1

Views

Author

Brendan McKay, Apr 15 2007

Keywords

Comments

Initial terms computed using software at http://users.cecs.anu.edu.au/~bdm/nauty/

Links

Crossrefs

Column k=8 of A328682.
Cf. A129426, A129436, A000421, A129417, A129419, A129421, A129423, A328682.

Programs

Formula

Inverse Euler transform of A129426. - Andrew Howroyd, Mar 17 2020

Extensions

Deleted a(0) and a(1). - N. J. A. Sloane, Jan 11 2020
a(1)=0 prepended and a(12)-a(18) from Andrew Howroyd, Mar 17 2020

A129423 Number of isomorphism classes of connected 7-regular loopless multigraphs of order 2n.

Original entry on oeis.org

1, 7, 263, 90614, 165041329, 861723619902, 10351918806321621, 253216618556625008961, 11542463442106815907796586, 915449471830886733265105097578
Offset: 1

Views

Author

Brendan McKay, Apr 15 2007

Keywords

Comments

Initial terms computed using software at http://users.cecs.anu.edu.au/~bdm/nauty/

Links

Crossrefs

Column k=7 of A328682.
Cf. A129424, A129434, A000421, A129417, A129419, A129421, A129425, A328682.

Programs

Formula

Inverse Euler transform of A129424. - Andrew Howroyd, Mar 21 2020

Extensions

a(7)-a(10) from Andrew Howroyd, Mar 21 2020

A243391 Number of isomorphism classes of connected 3-regular loopless multigraphs with n vertices and with semi-edges allowed.

Original entry on oeis.org

1, 3, 4, 12, 22, 68, 166, 534, 1589, 5464, 18579, 68320, 255424, 1000852, 4018156, 16671976, 70890940, 309439942, 1381815168, 6310880471, 29428287639, 140012980007, 678970863717, 3353545264060, 16857749613964, 86191265140699, 447951112379963, 2365177154077186
Offset: 1

Views

Author

Nico Van Cleemput, Jun 04 2014

Keywords

Comments

a(n) is also the number of isomorphism classes of connected loopless multigraphs with n vertices of degree 3 or less. - Andrew Howroyd, Mar 20 2020

Links

Crossrefs

Column k=3 of A334546.
Cf. A000421, A243392, A243393, A243394, A303030.

Extensions

a(23)-a(28) from Andrew Howroyd, Mar 20 2020

A243394 Number of isomorphism classes of connected 3-regular multigraphs with n vertices and with loops and semi-edges allowed.

Original entry on oeis.org

2, 5, 7, 22, 43, 141, 373, 1270, 4053, 14671, 52826, 203289, 795581, 3241367, 13504130, 57904671, 253856990, 1139231977, 5219113084, 24401837085, 116278408069, 564380686932, 2787884851040, 14007277302822, 71538337097031, 371197207327709, 1955833646495247, 10459788214042492
Offset: 1

Views

Author

Nico Van Cleemput, Jun 04 2014

Keywords

Comments

a(n) is also the number of isomorphism classes of connected multigraphs with n vertices of degree 3 or less and with loops allowed. - Andrew Howroyd, Mar 21 2020

Links

Crossrefs

Cf. A000421, A005967, A243391, A243392, A243393, A243394.

Extensions

a(23)-a(28) from Andrew Howroyd, Mar 21 2020

A005966 Number of trivalent planar loopless multigraphs with 2n nodes.

Original entry on oeis.org

1, 2, 5, 17, 71, 357, 2143, 14960, 116560, 986983, 8874072
Offset: 1

Views

Author

N. J. A. Sloane

Keywords

References

  • A. T. Balaban, Enumeration of Cyclic Graphs, pp. 63-105 of A. T. Balaban, ed., Chemical Applications of Graph Theory, Ac. Press, 1976; see p. 92.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A000421 (allowing non-planar), A005957 (allowing loops).

Programs

  • nauty
    for n in {1..10}; do geng -cqD3 $[2*$n] | planarg -q | multig -ur3; done # Sean A. Irvine, Oct 25 2016

Extensions

a(7)-a(11) and title improved by Sean A. Irvine, Oct 25 2016
Previous Showing 11-15 of 15 results.

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

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