Croatica Chemica Acta, Vol. 77 No. 1-2, 2004.
Original scientific paper
A New Hyper-Wiener Index
Ivan Gutman
; Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia and Montenegro
Abstract
If two edges e and f are deleted from a tree T, then it decomposes into three components, possessing, n0(e, f ), n1(e, f ), and n2(e, f ) vertices. Let n0(e, f ) count the vertices lying between the edges e and f. It is shown that the Wiener index W of the tree T is equal to the sum over all edges e of the products n1(e, e) • n2(e, e), and that the hyper-Wiener index WW of T is the sum over all pairs of edges e, f of the products n1(e, f ) • n2(e, f ). We now consider another structure-descriptor, denoted by WWW, equal to the sum over all pairs of edges of the products n0(e, f ) • n1(e, f ) • n2(e, f ). We establish some basic properties of WWW and show how it is related to W.
Keywords
Wiener index, W; hyper-Wiener index, WW; WWW index
Hrčak ID:
102646
URI
Publication date:
31.5.2004.
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