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A219189
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Parity of pi(5^n).
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0
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0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1
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OFFSET
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0
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COMMENTS
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The parity of pi(n) is obtained without calculating pi(n), and much more quickly. See the paper below.
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LINKS
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EXAMPLE
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a(4) = pi(5^4) mod 2 = 114 mod 2 = 0.
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MATHEMATICA
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Table[Mod[PrimePi[5^n], 2], {n, 10}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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