A070809 Cototient(totient(n))=A070556(n) is not a power of 2 and n is not a prime number.

1, 22, 25, 27, 33, 38, 44, 46, 49, 50, 54, 55, 57, 62, 63, 66, 69, 74, 75, 76, 77, 81, 82, 86, 88, 91, 92, 93, 94, 95, 98, 99, 100, 106, 108, 110, 111, 114, 115, 117, 118, 121, 122, 123, 124, 125, 126, 129, 132, 133, 134, 135, 138, 141, 142, 143, 146, 147, 148

Offset: 1

Author

Labos Elemer, May 08 2002

Keywords

• nonn

Examples

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

Crossrefs

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

Programs

Mathematica

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