OFFSET
1,2
COMMENTS
The maximal possible value of the ratio A348001(k)/A034444(k) is 1 which occurs at the terms of A348004.
The rounded values of the corresponding record values are 1, 0.5, 0.438, 0.406, 0.375, 0.359, 0.344, 0.312, 0.281, 0.266, 0.258, 0.250, 0.242, 0.199, 0.195, 0.170, 0.168, 0.145, ...
a(19) > 2*10^10, if it exists.
MATHEMATICA
f[p_, e_] := p^e - 1; uphi[1] = 1; uphi[n_] := Times @@ f @@@ FactorInteger[n]; r[n_] := Length @ Union[uphi /@ (d = Select[Divisors[n], CoprimeQ[#, n/#] &])]/Length[d]; rm = 2; seq = {}; Do[r1 = r[n]; If[r1 < rm, rm = r1; AppendTo[seq, n]], {n, 1, 10^5}]; seq
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Amiram Eldar, Sep 23 2021
STATUS
approved