%I #30 Jun 03 2023 09:30:49
%S 0,0,0,0,1,0,0,0,2,6,20,38,280,2900,28399,293059,3833587,60167732
%N Number of nontrivial (girth >=5) snarks on 2n nodes.
%C Snarks are cyclically 4-edge connected cubic graphs with chromatic index 4 and girth >= 5.
%H G. Brinkmann, J. Goedgebeur, J. Hagglund, and K. Markstrom, <a href="http://arxiv.org/abs/1206.6690">Generation and properties of Snarks</a>, arxiv 1206.6690 [math.CO], 2012-2013.
%H G. Brinkmann, J. Goedgebeur, J. Hagglund, and K. Markstrom, <a href="https://doi.org/10.1016/j.jctb.2013.05.001">Generation and properties of Snarks</a>, J. Comb. Theory, Series B, 103 (4) (2013), 468-488.
%H J. Hagglund and K. Markstrom, <a href="https://doi.org/10.1016/j.disc.2011.08.024">On stable cycles and cycle double covers of graphs with large circumference</a>, Discrete Math., 312 (2012), 2540-2544.
%H House of Graphs, <a href="https://houseofgraphs.org/meta-directory/snarks">Snarks</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Snark.html">Snark</a>
%K nonn,hard,more
%O 1,9
%A _Eric W. Weisstein_, May 22 2007
%E a(15), a(16) added from Hagglund-Markstrom by _N. J. A. Sloane_, Jul 26 2012
%E a(17), a(18) added by _Jan Goedgebeur_, Jul 31 2012