The Fibonacci numbers for the molecular graphs of two types of bent hexagonal chains

Abstract

The Fibonacci number of an undirected graph G=(V,E) is given by the number of subsets U of V such that no two vertices in U are adjacent. This number is one of the most popular topological indices in chemistry, which is called as the Merrifield-Simmons index there. Hexagonal chains are the graph representations of an important subclass of benzenoid molecules. In this contribution we follow our previous results on the Fibonacci number of the linear hexagonal chains. We obtain exact formulas for the Fibonacci numbers of two types of bent hexagonal chains.