1,3
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: A129056 A187708 A199837 * A033511 A189448 A200461
Adjacent sequences: A005331 A005332 A005333 * A005335 A005336 A005337
nonn
N. J. A. Sloane (njas(AT)research.att.com).