OFFSET
1,1
COMMENTS
Without the restrictions k > 1 and j > 1, 1 will be a term instead of 2 and 3. - Amiram Eldar, Apr 16 2024
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..53
MATHEMATICA
a = 0; Do[b = DivisorSigma[1, EulerPhi[n]]/DivisorSigma[1, n]; If[b > a, a = b; Print[n]], {n, 2, 10^7}]
PROG
(PARI) lista(kmax) = {my(rm = 0, f); for(k = 2, kmax, f = factor(k); r = sigma(eulerphi(f)) / sigma(f); if(r > rm, rm = r; print1(k, ", "))); } \\ Amiram Eldar, Apr 16 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jan 30 2002
EXTENSIONS
a(37)-a(39) added and name corrected by Amiram Eldar, Apr 16 2024
STATUS
approved