[Nauty] counting graphs

[Brendan McKay]

* Sterten at aol.com <Sterten at aol.com> [021204 21:26]:
> 
> So, apparently there are better methods to count graphs than geng.
> What methods are these ?

This is the Polya or Polya-Redfield method which uses group theory.
It is explained in many graph theory books.  It can also be
applied to some other classes of graphs, but not (easily) to
all classes.  For example, I believe that the exact enumeration
of triangle-free graphs is an open problem still.

Brendan.