VARIABLE SUM EXDEG INDICES OF CACTUS GRAPHS

摘要

For a graph G, the variable sum exdeg index SEIa(G) is defined as P u∈V (G) dG(u)a dG(u) , where a ∈ (0, 1) ∪ (1, +∞).In this work, we determine the minimum and maximum variable sum exdeg indices (for a > 1) of n-vertex cactus graphs with k cycles or p pendant vertices.Furthermore, the corresponding extremal cactus graphs are characterized.