For a graph, the forgotten topological index (F-index) is defined as the sum of cubes of degrees of vertices. In 2009, Eliasi and Taeri [M. Eliasi, B. Taeri, Four new sums of graphs and their wiener indices, Discrete Appl. Math. 157 (2009) 794-803] introduced four new sums (F-sums) of graphs. In this paper we study the F-index for the F-sums of some special well-known graphs.
Bulletin of Mathematical Sciences and Applications (Volume 16)
S. Ghobadi and M. Ghorbaninejad, "The Forgotten Topological Index of Four Operations on Some Special Graphs", Bulletin of Mathematical Sciences and Applications, Vol. 16, pp. 89-95, 2016