• Journal of applied mathematics & informatics
• /
• v.23 no.1_2
• /
• pp.329-335
• /
• 2007

A map is bisingular if each edge is either a loop or an isthmus (i.e., on the boundary of the same face). In this paper we study the number of rooted bisingular maps on the sphere and the torus, and we also present formula for such maps with four parameters: the root-valency, the number of isthmus, the number of planar loops and the number of essential loops.