OFFSET
1,1
COMMENTS
This sequence is finite, since by Grönwall's theorem sigma_3(n) <= sigma(n)^3 << (n log log n)^3 but phi(n)^4 >> (n/log log n)^4. - Charles R Greathouse IV, Nov 19 2015
FORMULA
Solutions to A001158(n) > phi(n)^4.
MATHEMATICA
Select[Range[500], DivisorSigma[3, #]>EulerPhi[#]^4&] (* Harvey P. Dale, Jun 21 2024 *)
PROG
(PARI) is(n)=my(f=factor(n)); sigma(f, 3)>eulerphi(f)^4 \\ Charles R Greathouse IV, Nov 19 2015
CROSSREFS
KEYWORD
nonn,fini
AUTHOR
Labos Elemer, Sep 27 2001
STATUS
approved