On the Extremal Mostar Indices of Hexagonal Chains

摘要

For a given graph G, the Mostar index Mo(G) is a bond-additive topological index as a measure of peripherality in G. Doslic et al. (2018) posed an open problem: Find extremal benzenoid chains, catacondensed benzenoids and general benzenoid graphs with respect to the Mostar index [7]. In this paper, we partially solve above problem, i.e., sharp upper and lower bounds on the Mostar indices among hexagonal chains with a given number of hexagons are determined, respectively. All the corresponding extremal hexagonal chains are characterized.