A098991 Numbers n where A098035(n)=0.

5, 9, 13, 15, 21, 27, 33, 35, 37, 39, 50, 55, 57, 61, 65, 73, 91, 93, 95, 111, 114, 115, 121, 122, 133, 141, 143, 145, 147, 155, 157, 170, 177, 183, 185, 189, 193, 195, 201, 205, 209, 213, 215, 217, 219, 231, 235, 247, 253, 259, 261, 277, 285, 295, 299, 301, 313

Offset: 1

Author

Leroy Quet and Robert G. Wilson v, Nov 05 2004

Keywords

• nonn

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..935 (terms < 5000)

Crossrefs

Cf. A098035.

Programs

Mathematica

f[n_] := Plus @@ MoebiusMu[Divisors[n] + 1]; Select[ Range[319], f[ # ] == 0 &]

PARI

a(n) = sumdiv(n, k, moebius(k + 1));
for(n=1, 320, if(a(n) == 0, print1(n,", "))) \\ Indranil Ghosh, Mar 16 2017

Formula

Sum_{k|n} mu(k+1), where mu() is Moebius function.