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

1,1

Links

Table of n, a(n) for n=1..71.

Mathematica

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

Prog

(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

Crossrefs

Cf. A002321.

Sequence in context: A114637 A009056 A065475 * A081311 A366935 A053233

Adjacent sequences: A062980 A062981 A062982 * A062984 A062985 A062986

Keyword

nonn

Author

Jason Earls, Jul 25 2001

Status

approved