A204199 Number of (strictly) 2-connected cubic graphs on 2n nodes.

0, 0, 0, 1, 4, 24, 139, 1046, 9398, 101668, 1278335, 18248616, 290147706, 5071909933

Offset: 1

Author

N. J. A. Sloane, Jan 12 2012

Keywords

• nonn
• more

Comments

The snarkhunter program (see Links) has options "C2" and "C3" for (at least) 2- and 3-connectivity respectively. So a(n) is the difference between the outputs from "./snarkhunter X 3 n C2" and "./snarkhunter X 3 n C3", where X=2n. - Ed Wynn, Jul 22 2023

Examples

			From _Ed Wynn_, Jul 22 2023: (Start)
For n=4, the unique 8-node cubic graph that is strictly 2-connected is:
   o-o
  /| |\
 o-o o-o
  \| |/
   o-o
(End)
		

Links

• G. Brinkmann, J. Goedgebeur and B. D. McKay, snarkhunter.
• F. C. Bussemaker, S. Cobeljic, L. M. Cvetkovic and J. J. Seidel, Computer investigations of cubic graphs, T.H.-Report 76-WSK-01, Technological University Eindhoven, Dept. Mathematics, 1976.

Crossrefs

Cf. A002851, A204198, A364404.

Extensions

a(8)-a(14) from Ed Wynn, Jul 22 2023