I will outlay a few observations applying to the harmonic numbers that may be interesting to prove (if it hasn't already been proven). From the Online Encyclopedia of Positive Integers we have: a(n) is the number of permutations p of {1,..,n} such that the minimum number of block interchanges required to sort the permutation p to the identity permutation is maximized. 1, 1, 5, 8, 84, 180, 3044, 8064, 193248, 604800 (oeis.org/A260695) Consider the following harmonic numbers: 1 + 1/2 = ((1 + 2)(1))/2! 1 + 1/2 + 1/3 + 1/4 = ((1 + 2 + 3 + 4)(5))/4! 1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 = ((1 + 2 + 3 + 4 + 5 + 6)(84))/6! 1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 + 1/7 + 1/8 = ((1 + 2 + 3 + 4 + 5 + 6 + 7 + 8)(3044))/8! and so on. Therefore, the following generalization suggests itself: 1 + 1/2 + 1/3 + 1/4 + ... + 1/2n = ((2n^2 + n)a(2n - 1))/(2n)! If this hasn't been proven, then I will leave it as a conjecture. Cheers, Robert