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 1-10 of 12 results. Next

A241715 Erroneous version of column k=7 of A128042.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 1, 6, 20
Offset: 1

Views

Author

Travis Hoppe and Anna Petrone, Apr 27 2014

Keywords

Comments

Number of simple connected graphs with n nodes and girth 7.
See A241711 for additional information.

Crossrefs

Cf. other simple connected graphs of girth k, A241711, A241712, A241713, A241714.

A128236 Number of n-node (unlabeled) graphs with girth 3.

Original entry on oeis.org

1, 4, 20, 118, 937, 11936, 272771, 11992996, 1018892793, 165089910412, 50502010570950, 29054155189364119, 31426485955571756316, 64001015703946097640927, 245935864153501211843554826
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

a(n) = A000088(n) - A006785(n).

Extensions

Corrected and extended by Martin Fuller, May 01 2015

A128243 Number of n-node (unlabeled) connected graphs with girth 6.

Original entry on oeis.org

0, 0, 0, 1, 1, 6, 17, 69, 239, 962, 3864, 17049, 79607, 403758, 2209386, 13138818, 84841130, 595825731
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

Programs

  • nauty
    geng -ctfq $n | countg -qg6 --ng # Martin Fuller, May 03 2015

Extensions

Corrected and extended by Martin Fuller, May 01 2015
a(18)-a(20) added by Georg Grasegger, May 02 2023

A128041 Triangle read by columns: number of n-node (unlabeled) graphs with girth k, for n >= 3, k >= 3.

Original entry on oeis.org

1, 4, 1, 20, 3, 1, 118, 15, 2, 1, 937, 59, 8, 2, 1, 11936, 296, 26, 9, 2, 1, 272771, 1604, 101, 28, 8, 2, 1, 11992996, 11303, 396, 107, 25, 9, 2, 1, 1018892793, 102108, 1744, 376, 92, 29, 9, 2, 1, 165089910412, 1250114, 8531, 1457, 321, 113, 30, 10, 2, 1
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Examples

			Number of n-node (unlabeled) graphs with girth k, for n >= 3, k >= 3.
.k..|.n=........3........4........5........6........7........8........9........10
---------------------------------------------------------------------------------
.0..|...........0........0........0........0........0........0........0.........0
.1..|...........0........0........0........0........0........0........0.........0
.2..|...........0........0........0........0........0........0........0.........0
.3..|...........1........4.......20......118......937....11936...272771..11992996
.4..|...........0........1........3.......15.......59......296.....1604.....11303
.5..|...........0........0........1........2........8.......26......101.......396
.6..|...........0........0........0........1........2........9.......28.......107
.7..|...........0........0........0........0........1........2........8........25
.8..|...........0........0........0........0........0........1........2.........9
.9..|...........0........0........0........0........0........0........1.........2
10..|...........0........0........0........0........0........0........0.........1
		

Crossrefs

Programs

Extensions

Corrected and extended by Martin Fuller, May 01 2015

A128237 Number of n-node (unlabeled) graphs with girth 4.

Original entry on oeis.org

0, 1, 3, 15, 59, 296, 1604, 11303, 102108, 1250114, 20738069, 467523871, 14230096759, 581439661069, 31720637440030
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

Formula

a(n) = A006785(n) - A006787(n).

Extensions

Corrected and extended by Martin Fuller, May 01 2015

A128240 Number of n-node (unlabeled) connected graphs with girth 3.

Original entry on oeis.org

0, 0, 1, 3, 15, 93, 794, 10850, 259700, 11706739, 1006609723, 164058686415, 50335888444167, 29003487017067011, 31397381129017616776, 63969560112658419275907, 245871831682052901418048916
Offset: 1

Views

Author

Keith Briggs, May 05 2007

Keywords

Comments

Number of unlabeled, connected graphs on n vertices with at least one induced subgraph isomorphic to a K_3, where K_3 is the complete graph on three vertices (a triangle). - Travis Hoppe and Anna Petrone, Jun 01 2014

Crossrefs

a(n) = A001349(n) - A024607(n).

Extensions

Corrected and extended by Martin Fuller, May 01 2015
Information added by Falk Hüffner, Nov 27 2015

A128241 Number of n-node (unlabeled) connected graphs with girth 4.

Original entry on oeis.org

0, 1, 2, 11, 41, 220, 1243, 9368, 89049, 1135894, 19381407, 445505570, 13741579905, 566739127723, 31124921885829
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

Formula

a(n) = A024607(n) - A126757(n). - Martin Fuller, May 01 2015

Extensions

Corrected and extended by Martin Fuller, May 01 2015

A325455 Triangle read by rows: T(n,k) is the number of simple connected graphs on n unlabeled nodes with circumference k, (n >= 3, k >= 3).

Original entry on oeis.org

1, 1, 3, 4, 6, 8, 10, 24, 24, 48, 30, 87, 116, 226, 383, 83, 342, 527, 1283, 2663, 6196, 257, 1324, 2644, 6644, 17613, 55468, 177083
Offset: 3

Views

Author

Andrew Howroyd, Sep 06 2019

Keywords

Comments

Trees are excluded since they do not have any cycle.

Examples

			Triangle begins:
    1;
    1,    3;
    4,    6,    8;
   10,   24,   24,   48;
   30,   87,  116,  226,   383;
   83,  342,  527, 1283,  2663,  6196;
  257, 1324, 2644, 6644, 17613, 55468, 177083;
  ...
		

Crossrefs

Right diagonal is A003216.
Row sums are A241841.

A128238 Number of n-node (unlabeled) graphs with girth 5.

Original entry on oeis.org

0, 0, 1, 2, 8, 26, 101, 396, 1744, 8531, 47803, 308086, 2300756, 19909540, 199365557
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

Programs

  • nauty
    geng -tfq $n | countg -qg5 --ng # Martin Fuller, May 03 2015

Extensions

Corrected and extended by Martin Fuller, May 01 2015

A128239 Number of n-node (unlabeled) graphs with girth 6.

Original entry on oeis.org

0, 0, 0, 1, 2, 9, 28, 107, 376, 1457, 5733, 24385, 110240, 540400, 2867847
Offset: 3

Views

Author

Keith Briggs, May 05 2007

Keywords

Crossrefs

Programs

  • nauty
    geng -tfq $n | countg -qg6 --ng # Martin Fuller, May 03 2015

Extensions

Corrected and extended by Martin Fuller, May 01 2015
Showing 1-10 of 12 results. Next