OFFSET
1,6
LINKS
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
KEYWORD
nonn,more
AUTHOR
Ed Wynn, Jul 22 2023
STATUS
approved