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%I #8 Dec 15 2017 17:35:18
%S 3,4,6,7,8,10,11,12,14,16,18,19,20,21,22,23,24,25,26,27,30,31,32,33,
%T 36,38,42,43,44,46,47,48,50,54,56,57,58,59,60,62,64,66,67,68,69,70,71,
%U 74,75,77,78,79,80,81,83,86,88,92,93,94,96,98,100,103,106,107,108,110,112
%N Half-totient function of n is not divisible by the number of divisors of n.
%C Half-totient function is phi(n)/2 for n >= 3, A023022.
%t Select[Range[3,120],!Divisible[EulerPhi[#]/2,DivisorSigma[0,#]]&] (* _Harvey P. Dale_, Mar 08 2013 *)
%o (PARI) j=[]; for(n=3,350, if(Mod(eulerphi(n)/2,numdiv(n)) !=0,j=concat(j,n))); j
%Y Cf. A023022.
%K nonn
%O 3,1
%A _Jason Earls_, Jul 24 2001
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