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.

User: Nico Van Cleemput

Nico Van Cleemput's wiki page.

Nico Van Cleemput has authored 9 sequences.

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

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

Extensions

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

A243393 Number of isomorphism classes of connected 3-regular loopless simple graphs with n vertices and with semi-edges allowed.

Original entry on oeis.org

1, 1, 2, 6, 10, 29, 64, 194, 531, 1733, 5524, 19430, 69322, 262044, 1016740, 4101318, 16996157, 72556640, 317558689, 1424644848, 6536588420, 30647561117, 146647344812, 715511358833, 3556531372395, 17996244725780, 92634418530686, 484756161038264
Offset: 1

Author

Nico Van Cleemput, Jun 04 2014

Keywords

Comments

Also: number of isomorphism classes of connected loopless simple graphs with maximum degree at most 3. - Brendan McKay, Mar 11 2020

Crossrefs

Extensions

a(24)-a(28) from Andrew Howroyd, Mar 20 2020

A243392 Number of isomorphism classes of connected 3-regular simple graphs of order 2n with loops and semi-edges allowed.

Original entry on oeis.org

2, 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

Author

Nico Van Cleemput, Jun 04 2014

Keywords

Crossrefs

Differs from A243391 only in the first term.

Extensions

a(23)-a(28) from Andrew Howroyd, May 06 2021

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

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

Crossrefs

Column k=3 of A334546.

Extensions

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

A198086 Number of isomorphism classes of nanocones with 5 pentagons and a symmetric boundary of length n.

Original entry on oeis.org

1, 5, 14, 41, 93, 212, 413, 797, 1399, 2424, 3941, 6317, 9686, 14654, 21451, 31025, 43754, 61042, 83484, 113084, 150732, 199211, 259804, 336263, 430401, 547166, 689034, 862426, 1070653, 1321891, 1620501, 1976744, 2396247, 2891749, 3470397, 4147802, 4932954, 5844785, 6894435, 8104688, 9489198
Offset: 5

Author

Nico Van Cleemput, Oct 21 2011

Keywords

Crossrefs

A198016 Number of isomorphism classes of nanocones with 4 pentagons and a nearsymmetric boundary of length n.

Original entry on oeis.org

2, 9, 32, 89, 204, 420, 786, 1376, 2272, 3589, 5450, 8021, 11474, 16032, 21928, 29452, 38902, 50645, 65056, 82585, 103692, 128920, 158822, 194044, 235240, 283165, 338586, 402377, 475422, 558724, 653296, 760276, 880814, 1016193, 1167708, 1336797, 1524908
Offset: 2

Author

Nico Van Cleemput, Oct 20 2011

Keywords

Formula

Conjectured g.f.: x^2*(-2*x^8 + 5*x^7 + x^6 + 13*x^5 + 8*x^4 + 13*x^3 + 9*x^2 + 3*x + 2)/(x^12 - 3*x^11 + 2*x^10 + x^9 - x^8 + 2*x^7 - 4*x^6 + 2*x^5 - x^4 + x^3 + 2*x^2 - 3*x + 1). [D. S. McNeil, Oct 20 2011]

A198015 Number of isomorphism classes of nanocones with 4 pentagons and a symmetric boundary of length n.

Original entry on oeis.org

1, 4, 16, 37, 89, 175, 336, 579, 975, 1533, 2363, 3477, 5030, 7040, 9716, 13078, 17400, 22707, 29342, 37336, 47112, 58705, 72627, 88918, 108185, 130476, 156502, 186315, 220741, 259839, 304554, 354953, 412111, 476101, 548137, 628299, 717946, 817168, 927478
Offset: 2

Author

Nico Van Cleemput, Oct 20 2011

Keywords

Formula

Conjectured g.f.: x^2*(-x^11 + x^10 - x^9 + 4*x^8 + 5*x^7 + 10*x^6 + 9*x^5 + 11*x^4 + 4*x^3 + 7*x^2 + 2*x + 1) / ((x - 1)^6*(x + 1)^3*(x^2 + 1)*(x^2 + x + 1)). [D. S. McNeil, Oct 20 2011]

A198014 Number of isomorphism classes of nanocones with 3 pentagons and a nearsymmetric boundary of length n.

Original entry on oeis.org

2, 8, 18, 37, 63, 104, 153, 224, 305, 413, 534, 688, 856, 1064, 1288, 1557, 1845, 2184, 2543, 2960, 3399, 3901, 4428, 5024, 5646, 6344, 7070, 7877, 8715, 9640, 10597, 11648, 12733, 13917, 15138, 16464, 17828, 19304, 20820, 22453, 24129, 25928, 27771, 29744
Offset: 1

Author

Nico Van Cleemput, Oct 20 2011

Keywords

Formula

Conjectured g.f.: (3*x^5 + 2*x^4 + 5*x^3 + 6*x^2 + 6*x + 2)*x/((x - 1)^4*(x + 1)^2*(x^2 + x + 1)). [D. S. McNeil, Oct 20 2011]

A197988 Number of isomorphism classes of nanocones with 3 pentagons and a symmetric boundary of length n.

Original entry on oeis.org

1, 3, 5, 12, 18, 31, 44, 67, 88, 124, 157, 207, 255, 323, 387, 476, 560, 671, 778, 915, 1046, 1212, 1371, 1567, 1757, 1987, 2209, 2476, 2734, 3039, 3336, 3683, 4020, 4412, 4793, 5231, 5659, 6147, 6623, 7164, 7692, 8287, 8870, 9523, 10162, 10876, 11575, 12351
Offset: 1

Author

Nico Van Cleemput, Oct 20 2011

Keywords

Formula

Conjectured g.f.: (x^7 + x^5 + x^4 + 2*x^3 + 2*x + 1)*x/((x - 1)^4*(x + 1)^2*(x^2 + x + 1)). [D. S. McNeil, Oct 20 2011]