0,4

Assumed to be weakly connected.

F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 219 (but there is an error).

R. C. Read (rcread(AT)math.uwaterloo.ca), email to N. J. A. Sloane (njas(AT)research.att.com), 28 August, 2000.

Eric Weisstein's World of Mathematics, Eulerian Graph

Cf. A058338.

Sequence in context: A039305 A124191 A065087 this_sequence A025503 A078124 A115245

Adjacent sequences: A058334 A058335 A058336 this_sequence A058338 A058339 A058340

nonn,nice,more

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