%N Number of simple connected graphs with n nodes that are Eulerian and have no subgraph isomorphic to diamond graph.
%H Travis Hoppe and Anna Petrone, <a href="https://github.com/thoppe/Encyclopedia-of-Finite-Graphs">Encyclopedia of Finite Graphs</a>
%Y Cf. A242790 (diamond free graphs), A003049 (Eulerian graphs).
%A _Travis Hoppe_ and _Anna Petrone_, Jun 06 2014