The number of vertices p of the (p, q) graph G.

The number of edges q of the (p, q) graph G.

The characteristic polynomial (over the integers) of the graph G; i.e. the characteristic polynomial of the adjacency matrix of G.

The spectrum of the graph G; i.e. the roots of the characteristic polynomial of G. The roots are returned as a set of tuples, each containing a root and its multiplicity.