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A084295
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n is such that pi(n*prime(n))/n is an integer.
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3
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1, 3, 47, 88, 200, 547, 12182, 15335, 39104, 58122, 73282, 150740, 480886
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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Do[s=PrimePi[n*Prime[n]]/n; If[IntegerQ[s], Print[n]], {n, 1, 100000}]
Select[Range[16000], IntegerQ[PrimePi[#*Prime[#]]/#]&] (* Harvey P. Dale, Jul 23 2015 *)
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PROG
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(PARI) isok(n) = denominator(primepi(n*prime(n))/n) == 1; \\ Michel Marcus, Sep 02 2019
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CROSSREFS
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KEYWORD
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nonn,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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