A073455 Numbers n such that to phi(n) = pi(n)-1.

6, 12, 18, 24, 42, 60

Offset: 1

Author

Labos Elemer, Aug 02 2002

Keywords

• fini
• full
• nonn

Examples

			9 primes below 24 = {2,3,5,7,11,13,17,19,23}; RRS[24]={1,5,7,11,13,17,19,23}, so 24 is here.
		

Crossrefs

Cf. A037228, A037171, A000010, A000720.

Programs

Mathematica

Do[s=EulerPhi[n]-PrimePi[n]; If[Equal[s, -1], Print[n]], {n, 1, 10000}]