A self-complementary graph is a graph which is isomorphic to its graph complement. The numbers of simple self-complementary graphs on n = 1, 2, ... nodes are 1, 0, 0, 1, 2, 0, 0, 10, ... (OEIS A000171). The first few of these correspond to the trivial graph on one node, the path graph P_4, and the cycle graph C_5.

graph complement | isomorphic graphs