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 13 results. Next

A054595 Number of labeled 2-connected minimally 2-edge-connected graphs by nodes.

Original entry on oeis.org

1, 3, 22, 255, 3321, 52948, 1064988, 25071525, 667694395, 20114706546, 678833013618, 25302305856919, 1033146095157645, 45956558123679960, 2213869047416018296, 114892917344393371209, 6396625360877830999983
Offset: 3

Views

Author

Sridar K. Pootheri (sridar(AT)math.uga.edu), Apr 14 2000

Keywords

Comments

The reference given here also contains the edge breakups for each node given here.

Crossrefs

A324417 Number of minimally 10-edge-connected non-isomorphic n-vertex graphs.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 25, 2498
Offset: 1

Views

Author

Jens M. Schmidt, Mar 03 2019

Keywords

Crossrefs

A054317 Number of unlabeled 2-connected minimally 2-edge-connected graphs with n nodes.

Original entry on oeis.org

1, 1, 2, 3, 5, 10, 19, 42, 92, 225, 564, 1501, 4127, 11809, 34713, 104904, 323778, 1019538, 3265502, 10624881, 35065697, 117289911, 397290416, 1362060455, 4724272231, 16572501190, 58782486855, 210782826628, 763991002957
Offset: 3

Views

Author

Sridar K. Pootheri (sridar(AT)math.uga.edu), Feb 25 2000

Keywords

Comments

References also contain the edge breakups for each term.

Crossrefs

A054596 Number of labeled minimally 2-edge-connected graphs by nodes.

Original entry on oeis.org

1, 3, 37, 435, 6996, 134428, 3094785, 82061325, 2473950880, 83606473566, 3132506471139, 128918727009163, 5784184164416490, 281105943314654760, 14716271275161095761, 825944690635111256697, 49490362937885427672552
Offset: 3

Views

Author

Sridar K. Pootheri (sridar(AT)math.uga.edu), Apr 14 2000

Keywords

Comments

The reference given here also contains the edge breakups for each node given here.

Crossrefs

A324410 Number of minimally 3-edge-connected non-isomorphic n-vertex graphs.

Original entry on oeis.org

0, 0, 0, 1, 1, 4, 8, 34, 118, 613, 3240, 20207
Offset: 1

Views

Author

Jens M. Schmidt, Feb 27 2019

Keywords

Crossrefs

A290011 Number of ways to connect n nodes with n+1 edges to form a 2-edge-connected graph.

Original entry on oeis.org

6, 85, 900, 9450, 104160, 1224720, 15422400, 207900000, 2993760000, 45924278400, 748280332800, 12913284384000, 235381386240000, 4520194398720000, 91233825306624000, 1931115968990208000, 42778526977105920000, 989887004576870400000, 23885015465274163200000
Offset: 4

Views

Author

Eugene Y. Q. Shen, Jul 17 2017

Keywords

Crossrefs

Programs

  • Maple
    seq((n^2 + 2 *n - 18)* n!/24, n=6..30); # Robert Israel, Jul 19 2017
  • Mathematica
    Table[(n - 4) (n!/8) + (n (n - 1)/2 - 3) (n!/12), {n, 4, 22}] (* Michael De Vlieger, Jul 18 2017 *)
  • PARI
    a(n) = (n - 4)*(n!/8) + (n*(n - 1)/2 - 3)*(n!/12); \\ Michel Marcus, Jul 18 2017

Formula

a(n) = (n - 4)*(n!/8) + (n*(n - 1)/2 - 3)*(n!/12) = (n^2 + 2 n - 18)*(n!/24).
E.g.f.: x^4*(3*x^2+x-6)/(24*(x-1)^3). - Robert Israel, Jul 19 2017

A177451 Partial sums of A054595.

Original entry on oeis.org

1, 4, 26, 281, 3602, 56550, 1121538, 26193063, 693887458, 20808594004, 699641607622, 26001947464541, 1059148042622186, 47015706166302146, 2260884753582320442, 117153802097975691651, 6513779162975806691634
Offset: 3

Views

Author

Jonathan Vos Post, May 09 2010

Keywords

Comments

Partial sums of number of labeled 2-connected minimally 2-edge-connected graphs by nodes. The only prime in the partial sum values shown is 281.

Examples

			a(6) = 1 + 3 + 22 + 255 = 281 is prime.
		

Crossrefs

Formula

a(n) = SUM[i=3..n] A054595(i).

A324411 Number of minimally 4-edge-connected non-isomorphic n-vertex graphs.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 5, 17, 114, 940, 11275, 167504
Offset: 1

Views

Author

Jens M. Schmidt, Feb 27 2019

Keywords

Crossrefs

A324412 Number of minimally 5-edge-connected non-isomorphic n-vertex graphs.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 1, 7, 32, 483, 10877, 386198
Offset: 1

Views

Author

Jens M. Schmidt, Feb 27 2019

Keywords

Crossrefs

A324413 Number of minimally 6-edge-connected non-isomorphic n-vertex graphs.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 1, 9, 71, 2516, 176323
Offset: 1

Views

Author

Jens M. Schmidt, Feb 27 2019

Keywords

Crossrefs

Showing 1-10 of 13 results. Next