An Enumeration of Certain Equivalence Classes of Directed Multigraphs Having 0 to 5 Nodes with Each Node Having 2 Incoming and 2 Outgoing Arcs
arXiv:math/9903144
Abstract
An enumeration is given of certain equivalence classes of directed multigraphs having 0 to 5 nodes with each node having 2 incoming and 2 outgoing arcs.
PDF file, 14 pages, 123 figures. Figures clarified, typos related to Classes 4,22,6 and 4,23,96 fixed