Extremal graphs with respect to the vert
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M.J. Nadjafi-Arani; G.H. Fath-Tabar; A.R. Ashrafi
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Article
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2009
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Elsevier Science
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English
β 377 KB
The vertex PI index of a graph G is the sum over all edges uv β E(G) of the number of vertices which are not equidistant to u and v. In this paper, the extremal values of this new topological index are computed. In particular, we prove that for each n-vertex graph 2 , where x denotes the greatest i