OFFSET
3,1
COMMENTS
Half-totient function is phi(n)/2 for n >= 3, A023022.
MATHEMATICA
Select[Range[3, 120], !Divisible[EulerPhi[#]/2, DivisorSigma[0, #]]&] (* Harvey P. Dale, Mar 08 2013 *)
PROG
(PARI) j=[]; for(n=3, 350, if(Mod(eulerphi(n)/2, numdiv(n)) !=0, j=concat(j, n))); j
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 24 2001
STATUS
approved