1,2
F. Harary and R. W. Robinson, Labeled bipartite blocks, Canad. J. Math., 31 (1979), 60-68.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Sequence in context: A186722 A060486 A002438 * A162087 A068531 A144139
Adjacent sequences: A005330 A005331 A005332 * A005334 A005335 A005336
nonn
N. J. A. Sloane (njas(AT)research.att.com).