New formulae for the decycling number of graphs
Han Ren, Chao Yang · Discussiones Mathematicae Graph Theory · 2018
A set S of vertices of a graph G is called a decycling set if G-S is acyclic. The minimum order of a decycling set is called the decycling number of G, and denoted by (G). Our results include: (a) For any graph G,