A319239 - OEIS

%I #5 Sep 16 2018 21:35:53

%S 1,2,3,5,7,8,11,13,16,17,19,23,24,27,29,30,31,32,36,37,40,41,42,43,47,

%T 53,54,56,59,60,61,64,66,67,70,71,73,78,79,81,83,84,88,89,90,96,97,

%U 100,101,102,103,104,105,107,109,110,113,114,120,125,126,127,128

%N Positions of nonzero terms in A316441, the list of coefficients in the expansion of Product_{n > 1} 1/(1 + 1/n^s).

%t facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];

%t Join@@Position[Table[Sum[(-1)^Length[f],{f,facs[n]}],{n,100}],_Integer?(Abs[#]>0&)]

%Y Complement of A319240.

%Y Cf. A001055, A045778, A114592, A162247, A190938, A281116, A281118, A303386, A316441, A319237.

%K nonn

%O 1,2

%A _Gus Wiseman_, Sep 15 2018