a Department of Mathematics, Suzhou University, Suzhou 215006, People's Republic of China
b Department of Mathematics, Northern Jiaotong University, Beijing 100044, People's Republic of China
Abstract:
In this paper rooted near-4-regular maps on the plane and the torus are counted with formulae with respect to four parameters: the root valency, the number of edges, the inner faces, and nonroot-vertex loops. In particular, the number of rooted near-4-regular maps on those surfaces with exactly k nonroot-vertex loops is investigated.