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A244797 Number of moduli m such that (prime(n) mod m) = 2.

%I A244797 #13 Mar 17 2024 16:05:33
%S A244797 0,0,1,1,2,1,3,1,3,3,1,3,3,1,5,3,3,1,3,3,1,3,4,3,3,5,1,7,1,3,3,3,7,1,
%T A244797 5,1,3,3,7,5,3,1,7,1,7,1,3,3,8,1,7,3,1,3,7,5,3,1,5,5,1,3,3,3,1,11,3,3,
%U A244797 7,1,7,7,3,3,3,3,5,3,7,3,3,1,7,1,3,8
%N A244797 Number of moduli m such that (prime(n) mod m) = 2.
%C A244797 Except for the initial 0,0, this is column 2 of the array at A244740.
%H A244797 Clark Kimberling, <a href="/A244797/b244797.txt">Table of n, a(n) for n = 1..1000</a>
%F A244797 a(n) = A032741(A040976(n)). - _Ridouane Oudra_, Mar 17 2024
%e A244797 prime(5) = 11 = (2 mod m) for m = 3, 9 so that a(5) = 2.
%t A244797 z = 300; f[n_, m_] := If[Mod[Prime[n], m] == 2, 1, 0];
%t A244797 t = Table[f[n, m], {n, 1, z}, {m, 1, Prime[n]}];
%t A244797 Table[Count[t[[k]], 1], {k, 1, z}] (* A244797 *)
%Y A244797 Cf. A244740, A244796, A244798.
%Y A244797 Cf. A032741, A040976.
%K A244797 nonn,easy
%O A244797 1,5
%A A244797 _Clark Kimberling_, Jul 06 2014