Kragujevac J. Math. 27

Kragujevac J. Math. 27 - 1 Kragujevac J. Math. (2005) 5-9.

MODIFIED WIENER INDICES OF THORN TREES

Bo Zhou

Department of Mathematics, South China Normal University,
Guangzhou 510631, P. R. China
(e-mail: zhoubo@scnu.edu.cn)

(Received December 14, 2004)

Abstract. The l-modified Wiener index ^mW_l provides a class of structure-descriptors to measure the branching of the carbon-atom skeleton molecules. A thorn tree is formed by attaching some new vertices of degree one to each vertex of the parent tree. An explicit expression is deduced enabling the calculation of the k-modified Wiener index of a type of thorn tree in terms of the i-modified Wiener indices of the parent tree for any natural number k with 0 Ł i Ł k.