1,4

a(1) could also be taken to be 0, but I prefer a(1) = 1. - N. J. A. Sloane (njas(AT)research.att.com), Oct 15 2006

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 219.

J. P. Dolch, Names of Hamiltonian graphs, Proc. 4th S-E Conf. Combin., Graph Theory, Computing, Congress. Numer. 8 (1973), 259-271.

Extended to n=11 by Brendan McKay (bdm(AT)cs.anu.edu.au), Jul 15 1996.

R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Sequence in context: A019016 A063859 A034183 this_sequence A146161 A019015 A000862

Adjacent sequences: A003213 A003214 A003215 this_sequence A003217 A003218 A003219

nonn,nice,hard

N. J. A. Sloane (njas(AT)research.att.com).