A079565 Number of unlabeled and connected graphs on n vertices which are either bipartite or co-bipartite. (G is bipartite iff the vertices can be partitioned into two sets such that all the edges in the graph go from one of these sets to the other. G is cobipartite iff the complement of G is bipartite.).

1, 1, 2, 6, 16, 49, 129, 481, 1854