Extremal polyomino chains with respect to general sum-connectivity index

For a (molecular) graph G, the general sum-connectivity index x alpha(G) is defined as the sum of the weights [d(u) + d(v)](alpha) of all edges uv of G, where d(u) (or d(v)) denotes the degree of a vertex u (or v) in G and alpha is an arbitrary real number. In this paper, we give an efficient formula for computing the general sum-connectivity index of polyomino chains and characterize the extremal polyomino chains with respect to this index, which generalizes one of the main results in [Z. Yarahmadi, A. Ashrafi, S. Moradi, Extremal polyomino chains with respect to Zagreb indices, Appl. Math. Lett. 25 (2012): 166-171].