%I #16 Sep 03 2019 17:46:54
%S 0,0,1,0,4,3,32,67,930
%N Number of simple connected class-2 graphs on n nodes.
%H Gordon Royle, <a href="http://people.csse.uwa.edu.au/gordon/graphs/#class2">Small Graphs: Class 2 Graphs</a>.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Class2Graph.html">Class 2 Graph</a>
%F a(n) = A001349(n) - A099436(n). - _Andrew Howroyd_, Sep 03 2019
%Y Cf. A001349 (number of connected graphs on n nodes).
%Y Cf. A099437 (number of simple class-2 graphs on n nodes).
%Y Cf. A099436 (number of connected class-1 graphs on n nodes).
%K nonn,more
%O 1,5
%A _Eric W. Weisstein_, Oct 15 2004