N-edged undirected graphs

  One edge : I
  Two edges : V
  Three edges there : Y, Z and Delta

These are called polynema too.

An OCaml program that outputs the set of N-edged graphs to a standard .dot file.


Best viewed with circo

Some Links :

If you are interested about number of these graphs
A nice talk about Polya theory

"Small graphs" from Gordon Royle