OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
EXAMPLE
a(2) = 3 since the harmonic mean of the divisors of 3 is 3/2.
a(3) = 2 since the harmonic mean of the divisors of 2 is 4/3.
MATHEMATICA
den[n_] := Denominator[DivisorSigma[0, n]/DivisorSigma[-1, n]]; seq[m_] := Module[{s = Table[0, {m}], c = 0, n = 1, i}, While[c < m, i = den[n]; If[i <= m && s[[i]] == 0, c++; s[[i]] = n]; n++]; s]; seq[100]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 30 2021
STATUS
approved