A062983 Mertens's function of n (A002321) is not divisible by phi(n).

3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77

Offset: 1

Author

Jason Earls, Jul 25 2001

Keywords

• nonn

Crossrefs

Cf. A002321.

Programs

Mathematica

M[n_]:= Sum[MoebiusMu[k], {k, 1, n}]; Select[Range[250], Mod[M[#], EulerPhi[#]]!=0 &] (* Indranil Ghosh, Mar 16 2017 *)

PARI

M(n)=sum(k=1,n,moebius(k)); j=[]; for(n=1,250, if(Mod(M(n),eulerphi(n))!=0,j=concat(j,n))); j