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A244797
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Number of moduli m such that (prime(n) mod m) = 2.
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4
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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, 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, 7, 1, 7, 7, 3, 3, 3, 3, 5, 3, 7, 3, 3, 1, 7, 1, 3, 8
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OFFSET
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1,5
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COMMENTS
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Except for the initial 0,0, this is column 2 of the array at A244740.
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LINKS
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FORMULA
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EXAMPLE
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prime(5) = 11 = (2 mod m) for m = 3, 9 so that a(5) = 2.
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MATHEMATICA
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z = 300; f[n_, m_] := If[Mod[Prime[n], m] == 2, 1, 0];
t = Table[f[n, m], {n, 1, z}, {m, 1, Prime[n]}];
Table[Count[t[[k]], 1], {k, 1, z}] (* A244797 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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