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%I #15 Jun 02 2024 11:05:19
%S 0,0,0,0,1,4,29,186,1435,12671,131820,1590900,21940512,339723835
%N Number of (strictly) 1-connected cubic graphs on 2n nodes.
%H G. Brinkmann, J. Goedgebeur and B. D. McKay, <a href="https://caagt.ugent.be/cubic/">snarkhunter</a>.
%e For n=5, the unique 10-node cubic graph that is strictly 1-connected is:
%e o o
%e /|\ /|\
%e o-o o-o o-o
%e \|/ \|/
%e o o
%o (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.
%Y Cf. A204199, A204198, A002851.
%K nonn,more
%O 1,6
%A _Ed Wynn_, Jul 22 2023