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Numbers n where A098035(n)=0.
1

%I #8 Mar 16 2017 04:19:33

%S 5,9,13,15,21,27,33,35,37,39,50,55,57,61,65,73,91,93,95,111,114,115,

%T 121,122,133,141,143,145,147,155,157,170,177,183,185,189,193,195,201,

%U 205,209,213,215,217,219,231,235,247,253,259,261,277,285,295,299,301,313

%N Numbers n where A098035(n)=0.

%H Indranil Ghosh, <a href="/A098991/b098991.txt">Table of n, a(n) for n = 1..935</a> (terms < 5000)

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

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

%o (PARI) a(n) = sumdiv(n, k, moebius(k + 1));

%o for(n=1, 320, if(a(n) == 0, print1(n,", "))) \\ _Indranil Ghosh_, Mar 16 2017

%Y Cf. A098035.

%K nonn

%O 1,1

%A _Leroy Quet_ and _Robert G. Wilson v_, Nov 05 2004