Variable Viscosity and Chemical Reaction Effects on MHD Flow of Radiative Fluid Past a Stretching Sheet in the Presence of Joule Heating

In this paper, we introduced new index from the Zagreb index family, named as -index is defined as the sum of degree five of all the vertices of a graph. We derive the -index of some different graph operations such that Join, Cartesian product, Composition, Corona product, Tensor Product, Strong product, Disjunction, Symmetric difference, Corona join product, Subdivision vertex join are obtained.