Computing the Szeged index of third and fourth dendrimer nanostars

Let e be an edge of a graph, G, connecting the vertices u and v. Define two sets N₁(e|G) and N₂(e|G) as N₁(e|G) = {x isin V(G)|d(x, u) < d(x, v)} and N₂(e|G) = {x isin V(G)|d(x, v) < d(x, u)}. The number of elements of N₁(e|G) and N₂(e|G) are denoted by n₁(e|G) and n₂(e|G), respectively. The Szeged index of the graph G is defined as Sz(G) = Sigma_eisinE(G)n₁(e|G) n₂(e|G). In this Letter, the Szeged index of third and fourth dendrimer nanostars is computed.