Balaban index of C4C8(S) nanotubes

Let G be a simple connected graph. the Balaban index of a G is defined as which m is the number of edges, μ is the cyclomatic number of G, d(u) is the sum of the distance between vertex u and all of the vertices of G and the summation goes over all edges from the edge set E(G). In this paper we obtain a method to compute the Balaban index of the nanotubes which have square and octagon structure and denoted by C4C8(S).