[seqfan] Re: Number of Euler graphs: A002854 or something else?
N. J. A. Sloane
njas at research.att.com
Thu Jan 28 17:59:58 CET 2010
Max, I think you have misunderstood the definition of Euler graph.
An Euler graph is a graph with every node having even degree.
I will add a comment to A002854 to clarify this.
References for this definition are
1. the "classic" paper which underlies A002854, namely
%D A002854 C. L. Mallows and N. J. A. Sloane, Two-graphs, switching classes and Euler graphs are equal in number, SIAM J. Appl. Math., 28 (1975), 876-880.
(did you look at it?)
and 2. the earlier references that it cites.
Your definition :
> Let us assume the conventional definition of Euler graphs:
> a graph is Euler if there exists an Euler cycle, i.e., a cycle that
> goes through every edge in the graph exactly once.
is not right.
As you say, one should be very careful before changing the classic sequences!
Neil
More information about the SeqFan
mailing list