OFFSET
1,1
COMMENTS
For numbers in A014567, we have A017665(n) = numerator(sigma(n)/n) = sigma(n) = A000203(n), so A017665(n) > n.
For numbers in A069059, since both terms of the fraction are divided by their GCD, A009194(n), we will have A017665(n) < A000203(n).
Here we are interested in terms of A069059 for which we still have A017665(n) > n, despite the division by the GCD.
Numbers such that sigma(n)/n > gcd(sigma(n), n) > 1. - Charlie Neder, Sep 08 2018
LINKS
Charlie Neder, Table of n, a(n) for n = 1..6892 (Terms < 10^6)
EXAMPLE
MATHEMATICA
gnQ[n_]:=Module[{s=DivisorSigma[1, n]}, GCD[s, n]!=1&&Numerator[s/n]>n]; Select[ Range[ 3100], gnQ] (* Harvey P. Dale, Jan 03 2018 *)
PROG
(PARI) isok(n) = (gcd(sigma(n), n) != 1) && (numerator(sigma(n)/n) > n);
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
Michel Marcus, Dec 28 2013
STATUS
approved