A Note on Counting Connected Graph Covering Projections
Michael Hofmeister · SIAM Journal on Discrete Mathematics · 1998
During the last decade, a lot of progress has been made in the enumerative branch of topological graph theory. Enumeration formulas were developed for a large class of graph covering projections. The purpose of this paper is to count graph covering projections of graphs such that the corresponding covering space is a connected graph. The main tool of the enumeration is Pólya's theorem.