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

Author

Stuart E Anderson, Mar 16 2011

Keywords

• nonn
• more
• hard

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

• 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]

Crossrefs

Cf. A034889, A181340, A187928, A000944.

Programs

plantri

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

Extensions

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