two types of geometric–arithmetic index of v–phenylenic nanotube

the concept of geometric-arithmetic indices was introduced in the chemical graph theory.these indices are defined by the following general formula:   ( )2( ) uv e g u vu vq qq qga g ,where qu is some quantity that in a unique manner can be associated with the vertex u ofgraph g. in this paper the exact formula for two types of geometric-arithmetic index of vphenylenicnanotube are given.