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A219098
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Parity of primepi(3^n).
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2
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0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0
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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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For n = 4, primepi(3^4) = 22 = 0 (mod 2).
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MATHEMATICA
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Table[Mod[PrimePi[3^n], 2], {n, 0, 25}] (* T. D. Noe, Nov 12 2012 *)
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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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