OFFSET
1,2
EXAMPLE
The elements of the continued fractions of the harmonic mean of the divisors of the first 10 terms are:
n a(n) elements
-- ---- --------
1 1 1
2 6 2
3 24 3,5
4 170 4,5,16
5 140 5
6 270 6
7 1140 8,7
8 630 8,13
9 1400 9,31
10 4420 10,44,10
MATHEMATICA
f[n_] := Min[ContinuedFraction[DivisorSigma[0, n] / DivisorSigma[-1, n]]]; seq[len_, nmax_] := Module[{s = Table[0, {len}], c = 0, n = 1, i}, While[c < len && n < nmax, i = f[n]; If[i <= len && s[[i]] == 0, c++; s[[i]] = n]; n++]; s]; seq[25, 10^6]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Nov 20 2021
STATUS
approved