Operations Research Transactions ›› 2015, Vol. 19 ›› Issue (2): 45-53.doi: 10.15960/j.cnki.issn.1007-6093.2015.02.005

Previous Articles     Next Articles

The Harary index of tricyclic graphs

CAI Gaixiang1,*, XING Baohua1, YU Guidong1   

  1. 1. School of Mathematics and Computation Sciences, Anqing Normal University, Anqing 246133, Anhui, China
  • Received:2014-06-23 Online:2015-06-15 Published:2015-06-15

Abstract:

The Harary index is defined as the sum of reciprocals of distances between all pairs of vertices of a  graph. Tricyclic graphs are  connected graphs in which the number of edges equals the number of vertices plus two. In this paper, we determine graphs with the largest Harary index among all the tricyclic graphs, and we also give graphs with the second largest Harary index among all the tricyclic graphs with three cycles.

Key words: Harary index, tricyclic graph, distance