Journal of Prime Research in Mathematics

# Forgotten index of generalized F-sum graphs

H. M. Awais
Department of Mathematics, School of Science, University of Management and Technology, Lahore, Pakistan.
M. Javaid
Department of Mathematics, School of Science, University of Management and Technology, Lahore, Pakistan.
M. Jamal
Department of Mathematics and Statistics, PMAS-Arid Agriculture University, Rawalpindi, Pakistan.

$$^{1}$$Corresponding Author: hmawais.umt@gmail.com

### Abstract

Liu et al. [IEEE Access; 7(2019); 105479-105488] defined the concept of the generalized subdivided operations on graphs and obtained the generalized F-sum graphs. They also calculated the 1st and 2nd Zagreb indices of the generalized F-sum graphs. In the continuation of this work, we study the forgotten index (F-index) of the generalized F-sum graphs in terms of different topological indices (TI’s) of their base graphs. In the end, the results of F-index on the generalized F-sum graphs acquired by the particular classes of alkane are also included.

#### Keywords:

Generalized operations; Zagreb indices; F-index.