A086216 Number of 4-connected unlabeled n-node graphs.

0, 0, 0, 0, 1, 4, 25, 384, 14480, 1211735, 184649399, 47952362294

Offset

1,6

Comments

The definition means that the connectivity is 4 or more.

Links

Table of n, a(n) for n=1..12.

Travis Hoppe and Anna Petrone, Integer sequence discovery from small graphs, arXiv preprint arXiv:1408.3644, [math.CO], 2014.

Travis Hoppe and Anna Petrone, Integer sequence discovery from small graphs, Discr. Appl. Math. 201 (2016) 172-181.

Eric Weisstein's World of Mathematics, k-Connected Graph

Formula

a(n) = A086217(n) + A052445(n). - Andrew Howroyd, Sep 04 2019

Example

There are 4 different 4-connected graphs on 6 vertices. - Dylan Thurston, Jun 18 2009

Crossrefs

See A052445 for exactly-4-connected graphs.

See A086217 for 5-connected graphs.

See A259862 for further information.

Sequence in context: A093959 A308476 A222902 * A167041 A123129 A075577

Adjacent sequences: A086213 A086214 A086215 * A086217 A086218 A086219

Keyword

nonn,hard,more,changed

Author

Eric W. Weisstein, Jul 12 2003

Extensions

Offset corrected by Dylan Thurston, Jun 18 2009

a(10) from the Encyclopedia of Finite Graphs (Travis Hoppe and Anna Petrone), Apr 11 2014

Minor edits by N. J. A. Sloane, Jul 08 2015 at the suggestion of Brendan McKay.

a(12) added by Georg Grasegger, Jan 07 2025

Status

approved