1,4

a(1) could also be taken to be 0, but I prefer a(1) = 1. - njas, Oct 15 2006

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.

Adjacent sequences: A003213 A003214 A003215 this_sequence A003217 A003218 A003219

Sequence in context: A019016 A063859 A034183 this_sequence A146161 A019015 A000862

nonn,nice,hard

njas