F-index of Total Transformation Graphs
  The F-index of a graph $G$ is the sum of the cubes of the degrees of the vertices of $G$. In this paper, explicit expressions for the F-index of different transformation graphs of type ${{G}^{xyz}}$ with $x, y, z\in \{-, + \}$ are obtained. F-index for semitotal point graph and semitotal line graph are also obtained here. 
Nilanjan De
cs.DM