A086216 - OEIS

A086216

Number of 4-connected unlabeled n-node graphs.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

COMMENTS

The definition means that the connectivity is 4 or more.

LINKS

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

T. Hoppe and A. 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.

KEYWORD

nonn,hard,more

AUTHOR

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.

STATUS

approved