The general connectivity indices of catacondensed hexagonal systems

摘要

The general connectivity index R _α(G) of a graph G is defined as , where uv is an edge of and α ≠ 0. In this paper, a formula is given for computing the general connectivity indices R _α of catacondensed hexagonal systems. We show that the general connectivity index R _α is monotone decreasing over the number of inlets in the system. The catacondensed hexagonal systems with the first up to the third extremal general connectivity indices are completely characterized.