Lucas Sequences in Subgraph Counts of Series-Parallel and Related Graphs
Eric M. Neufeld, Charles J. Colbourn · The Fibonacci Quarterly · 1985
We follow graph theoretic terminology as in [B&M]. Let G = (V 9 E) denote a graph where V is a set of vertices and E is a set of nonoriented edges. Though we do not in general consider graphs with loops or multiple edg£s,we make reference to such graphs for the purpose of proofs. When an edge e appears m