A187927 Number of embeddings on the sphere of 2-connected planar graphs, minimum vertex degree 3, with n nodes.

2, 13, 163, 2067, 30953, 486674, 7957459, 133344454, 2280001754, 39648557743, 699731146514, 12511186297320

Offset

6,1

Comments

The graphs are exactly 2-connected, not at least 2-connected. The graphs were enumerated using plantri (by B.D. McKay & G. Brinkmann) for the purpose of finding compound perfect squared squares.

Links

Table of n, a(n) for n=6..17.

Stuart Anderson, Compound Perfect Squared Squares

S. E. Anderson, Compound Perfect Squared Squares of the Order Twenties, 2013.

Gunnar Brinkmann and Brendan McKay, Plantri Guide

Gunnar Brinkmann and Brendan McKay, Guide to using plantri [Cached copy, with permission]

Prog

(plantri) plantri -p -c2 -m3 -x -u -v n  ; or

Crossrefs

Cf. A034889, A181340, A187928, A000944.

Sequence in context: A192563 A014507 A132614 * A252766 A098638 A090643

Adjacent sequences: A187924 A187925 A187926 * A187928 A187929 A187930

Keyword

nonn,more,hard

Author

Stuart E Anderson, Mar 16 2011

Extensions

a(15)-a(17) from Lorenz Milla, Oct 08 2013

Status

approved