OFFSET
1,2
MATHEMATICA
Select[Range[150], EulerPhi[DivisorSigma[1, #]] <= EulerPhi[#] &] (* Amiram Eldar, May 06 2022 *)
PROG
(PARI) isA353685(n) = (eulerphi(sigma(n))<=eulerphi(n));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 06 2022
STATUS
approved