Das, Kinkar C.Xu, KexiangÇevik, Ahmet SinanGraovac, Ante2022-09-302022-09-302013Das, K. C. vd. (2013). "On the Harary index of graph operations". Journal of Inequalities and Applications, 2013.1029-242Xhttps://doi.org/10.1186/1029-242X-2013-339https://journalofinequalitiesandapplications.springeropen.com/articles/10.1186/1029-242X-2013-339http://hdl.handle.net/11452/28910The Harary index is defined as the sum of reciprocals of distances between all pairs of vertices of a connected graph. In this paper, expressions for the Harary indices of the join, corona product, Cartesian product, composition and disjunction of graphs are derived and the indices for some well-known graphs are evaluated. In derivations some terms appear which are similar to the Harary index and we name them the second and third Harary index.eninfo:eu-repo/semantics/openAccessMathematicsGraphHarary indexGraph operationsWiener indexTopological indexesHyper-wienerTreesArticle0003236637000012-s2.0-848944270522013Mathematics, appliedMathematicsGraph; Unicyclic Graph; Vertex Degree