%I #13 Oct 30 2021 10:41:35
%S 1,6,3,2,5,270,7,672,84,30,11,4,13,18620,420,24,17,12,19,10,21,22,23,
%T 30240,1550,78,9,168,29,60,31,8,132,102,35,18,37,38,39,3360,41,3724,
%U 43,7392,45,15456,47,1080,49,6051500,153,26,53,540,55,56,57,174,59,90
%N a(n) is the least number k such that the numerator of the harmonic mean of the divisors of k is equal to n, or 1 if no such k exists.
%H Amiram Eldar, <a href="/A348694/b348694.txt">Table of n, a(n) for n = 1..179</a>
%H Amiram Eldar, <a href="/A348694/a348694.txt">Table of n, a(n) for n = 1..1000 with 9 holes marked with 0</a>
%e a(2) = 6 since the harmonic mean of the divisors of 6 is 2.
%e a(3) = 3 since the harmonic mean of the divisors of 3 is 3/2.
%t num[n_] := Numerator[DivisorSigma[0, n]/DivisorSigma[1, n]]; seq[m_] := Module[{s = Table[0, {m}], c = 0, n = 1, i}, While[c < m, i = num[n]; If[i <= m && s[[i]] == 0, c++; s[[i]] = n]; n++]; s]; seq[100]
%Y Cf. A099377, A099378, A348695.
%K nonn
%O 1,2
%A _Amiram Eldar_, Oct 30 2021
