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Cototient(totient(n))=A070556(n) is not a power of 2 and n is not a prime number.
4

%I #4 Oct 15 2013 22:31:19

%S 1,22,25,27,33,38,44,46,49,50,54,55,57,62,63,66,69,74,75,76,77,81,82,

%T 86,88,91,92,93,94,95,98,99,100,106,108,110,111,114,115,117,118,121,

%U 122,123,124,125,126,129,132,133,134,135,138,141,142,143,146,147,148

%N Cototient(totient(n))=A070556(n) is not a power of 2 and n is not a prime number.

%e n=95: Phi[95]=72,cototient[72]=72-phi[72]=72-24-=48 is not a power of 2.

%t Do[s= EulerPhi[n]-EulerPhi[EulerPhi[n]]; If[ !IntegerQ[Log[2, s]]&&!PrimeQ[n], Print[n]], {n, 1, 1000}]

%Y Cf. A070556, A051953, A054571, A070806, A070807, A070810, A070811.

%K nonn

%O 1,2

%A _Labos Elemer_, May 08 2002