A364404 Number of (strictly) 1-connected cubic graphs on 2n nodes.

0, 0, 0, 0, 1, 4, 29, 186, 1435, 12671, 131820, 1590900, 21940512, 339723835

Offset

1,6

Links

Table of n, a(n) for n=1..14.

G. Brinkmann, J. Goedgebeur and B. D. McKay, snarkhunter.

Example

For n=5, the unique 10-node cubic graph that is strictly 1-connected is:
   o     o
  /|\   /|\
 o-o o-o o-o
  \|/   \|/
   o     o

Prog

(nauty) # The snarkhunter program (see Links) has an option "C2" for (at least) 2-connectivity. So a(n) is the difference between the outputs from "./snarkhunter X 3 ns" and "./snarkhunter X 3 ns C2", where X=2n.

Crossrefs

Cf. A204199, A204198, A002851.

Sequence in context: A198794 A258416 A079885 * A121191 A129587 A143551

Adjacent sequences: A364401 A364402 A364403 * A364405 A364406 A364407

Keyword

nonn,more

Author

Ed Wynn, Jul 22 2023

Status

approved