The frst Zagreb and forgotten topological indices of d-ary trees

Abstract

The rst Zagreb index of a graph is equal to the sum of the square ofthe vertex degrees of the graph and the forgotten topological index (Findex)of a graph is dened as the sum of cubes of the vertex degrees ofthe graph. These parameters have applications in chemistry and drugstructures. For any xed integer d ≥ 2, the d-ary tree is a rooted treein which each node has no more than d children. We determine themean value of these indices in d-ary trees. Also, we obtain some usefulrelations and equalities related to these indices and other graphicalparameters.