A short note on inverse sum indeg index of graphs.

The inverse sum indeg index of a graph G is defined as ISI (G) = ∑ u v ∈ E (G) d (u) d (v) d (u) + d (v) , where d (u) is the degree of the vertex u. In a recent paper, Pattabiraman [Inverse sum indeg index of graphs, AKCE Int. J. Graphs Combinat. 15(2) (2018) 155–167] gave some lower and upper bounds on ISI index of all connected graphs in terms of Harmonic index, second Zagreb index and hyper Zagreb index. But some results were erroneous. In this note, we have corrected these results. [ABSTRACT FROM AUTHOR]