• Communications of the Korean Mathematical Society
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• v.36 no.2
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• pp.389-400
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• 2021

For a graph G, the variable sum exdeg index SEI_a(G) is defined as Σ_u∈V(G)d_G(u)a^d_G(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.