Computing Vertex Pi Index of Tetrathiafulvalene Dendrimers

General formulas are obtained for the vertex padmakar-ivan index (piv) of tetrathiafulvalene (ttf) dendrimer, whereby ttf units we are employed as branching centers. the piv index is a wiener-szeged-like index developed very recently. this topological index is defined as the summation of all sums of nu(e) and nv(e), over all edges of connected graph g.