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SOME INEQUALITIES FOR THE HARMONIC TOPOLOGICAL INDEX

  • MILOVANOVIC, E.I. (Department of Computer Science, Faculty of Electronic Engineering, University of Nis) ;
  • MATEJIC, M.M. (Department of Mathematics, Faculty of Electronic Engineering, University of Nis) ;
  • MILOVANOVIC, I.Z. (Department of Mathematics, Faculty of Electronic Engineering, University of Nis)
  • Received : 2017.05.07
  • Accepted : 2018.01.13
  • Published : 2018.05.30

Abstract

Let G be a simple connected graph with n vertices and m edges, with a sequence of vertex degrees $d_1{\geq}d_2{\geq}{\cdots}{\geq}d_n$ > 0. A vertex-degree topological index, referred to as harmonic index, is defined as $H={\sum{_{i{\sim}j}}{\frac{2}{d_i+d_j}}$, where i ~ j denotes the adjacency of vertices i and j. Lower and upper bounds of the index H are obtained.

Keywords

References

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