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 31-40 of 49 results. Next

A325447 Triangle read by rows: T(n,k) is the number of simple nonseparable (or 2-connected) graphs on n unlabeled nodes with circumference k, (n >= 3, k >= 3).

Original entry on oeis.org

1, 0, 3, 0, 2, 8, 0, 2, 6, 48, 0, 2, 9, 74, 383, 0, 2, 10, 159, 756, 6196, 0, 2, 13, 276, 2058, 14634, 177083, 0, 2, 14, 505, 4824, 48137, 384942, 9305118
Offset: 3

Views

Author

Andrew Howroyd, Sep 06 2019

Keywords

Examples

			Triangle begins, (n >= 3, k >= 3):
  1;
  0, 3;
  0, 2,  8;
  0, 2,  6,  48;
  0, 2,  9,  74,  383;
  0, 2, 10, 159,  756,  6196;
  0, 2, 13, 276, 2058, 14634, 177083;
  0, 2, 14, 505, 4824, 48137, 384942, 9305118;
  ...
		

Crossrefs

Row sums are A002218(n >= 3).
Right diagonal is A003216.

Formula

T(n, 4) = 2 for n > 4.

A243321 Number of simple connected graphs with n nodes that are bipartite and planar.

Original entry on oeis.org

1, 1, 1, 3, 5, 16, 41, 158, 582, 2749, 13852, 80341, 503582, 3419670, 24533162, 184227017
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 03 2014

Keywords

Crossrefs

Cf. A003216 (bipartite graphs), A003094 (planar graphs).

Programs

  • Mathematica
    A164099 = Cases[Import["https://oeis.org/A164099/b164099.txt", "Table"], {, }][[All, 2]];
    (* EulerInvTransform is defined in A022562 *)
    EulerInvTransform[{0} ~Join~ A164099 + 1] (* Jean-François Alcover, Dec 03 2019, updated Mar 17 2020 *)

Formula

Inverse Euler transform of (A164099 + 1). - Falk Hüffner, May 10 2019

Extensions

a(11)-a(16) added using tinygraph by Falk Hüffner, May 10 2019

A243270 Number of unlabeled simple graphs with n nodes that are Hamiltonian and bipartite.

Original entry on oeis.org

1, 0, 0, 1, 0, 4, 0, 24, 0, 473, 0, 30512, 0, 6374556
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A005142 (bipartite graphs).

Extensions

a(11)-a(14) added using tinygraph by Falk Hüffner, Aug 13 2017

A243271 Number of unlabeled simple graphs with n nodes that are Hamiltonian and distance-regular.

Original entry on oeis.org

1, 0, 1, 2, 2, 4, 2, 5, 4, 6
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A241814 (distance-regular graphs).

A243272 Number of unlabeled simple graphs with n nodes that are Hamiltonian and Eulerian.

Original entry on oeis.org

1, 0, 1, 1, 2, 5, 21, 120, 1312, 26525, 1073690, 84471633
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A003049 (Eulerian graphs).

Extensions

a(10)-a(11) added using tinygraph by Falk Hüffner, Aug 15 2017

A243273 Number of unlabeled simple graphs with n nodes that are Hamiltonian and integral.

Original entry on oeis.org

0, 0, 0, 1, 7, 43, 379, 6185, 177071, 9305068
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A064731 (integral graphs).

A243274 Number of graphs with n nodes that are Hamiltonian and non-integral.

Original entry on oeis.org

1, 0, 1, 2, 1, 5, 4, 11, 12, 50
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A064731 (integral graphs), A241842 (non-integral graphs).

A243275 Number of graphs with n nodes that are Hamiltonian and triangle-free.

Original entry on oeis.org

1, 0, 0, 1, 1, 4, 5, 35, 130, 1293, 13529, 232852, 5009335, 147950020
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Crossrefs

Cf. A003216 (Hamiltonian graphs), A024607 (connected triangle-free graphs).

Extensions

a(11)-a(14) added using tinygraph by Falk Hüffner, Aug 15 2017

A243276 Number of graphs with n nodes that are Hamiltonian and have no induced subgraph isomorphic to K_4.

Original entry on oeis.org

1, 0, 1, 2, 5, 29, 188, 2481, 52499, 1857651, 104392105
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 02 2014

Keywords

Comments

K_4 is the complete graph on four vertices.

Crossrefs

Cf. A003216 (Hamiltonian graphs), A079574 (connected K_4 free graphs).

Extensions

a(11) added using tinygraph by Falk Hüffner, Aug 13 2017

A243319 Number of simple connected graphs with n nodes that are bipartite and distance regular.

Original entry on oeis.org

1, 1, 0, 1, 0, 2, 0, 3, 0, 3
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Jun 03 2014

Keywords

Crossrefs

Cf. A003216 (bipartite graphs), A241814 (distance regular graphs).
Previous Showing 31-40 of 49 results. Next