OFFSET
1,2
COMMENTS
Apparently, most of the terms m have h(m+1) > h(m) and numerator(delta(m)) = 1.
Can two consecutive numbers have the same harmonic mean of divisors? If yes, then this sequence is finite.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..86
EXAMPLE
The values of delta(k) for the first terms are 0.333..., 0.166..., 0.047..., 0.0357..., ...
MATHEMATICA
h[n_] := n * DivisorSigma[0, n]/DivisorSigma[1, n]; dm = 1; h1 = h[1]; s = {}; Do[h2 = h[n]; d = Abs[h2 - h1]; If[d < dm, dm = d; AppendTo[s, n-1]]; h1 = h2, {n, 2, 10^5}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, May 30 2020
STATUS
approved