On the Wiener Number of Thorn Trees, Stars, Rings, and Rods

Sa？etak The concept of thorn graphs proposed recently by Gutman is extended to the broader concept of generalized thorny graphs. The latter preserve unchanged certain parts of the parent graph while applying the procedure of thorn graph generation to the rest of the graph. Thorn stars and rods are typical examples of such generalized thorn graphs, owing to the unchanged star center, and the other-than-terminal rod vertices. Formulae are presented for the Wiener number of these and other classes of (generalized) thorn graphs