Reciprocal version of product degree distance of cactus graphs

Abstract

The reciprocal version of product degree distance is a product degree weighted version of Harary index defined for a connected graph G as RDD*(G) = Sigma({x, y}subset of V(G) )(d(G)(x).d(G)(y))/d(G)(x,y), where d(G)(x) is the degree of the vertex x and d(G)(x, y) is the distance from x to y in G. This article is attain the value of RDD* of different types of cactus such as triangular, square and hexagonal chain cactus graphs.