... me to the area of log-concave sequences.AbstractWe provide a combinatorial proof for the fact that for any fixed n, the sequence{i(n, k )}0≤k ≤(n2) of the numbers of permutations of length ... i(p) of inversions, and the study of numbersi(n, k)ofn-permutations having k inversions, is a classic area of combinatorics. The best-known result is the following [4].Theorem 1.1 Let n ≥ 2. Then ... 71–89.[3] P. A. MacMahon, The indices of permutations, and the derivation therefrom of func-tions of a single variable associated with the permutations of any assemblage of objects, Amer. J. Math....