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A136583
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n such that floor(sqrt(10^(2*n-1))) is (probably) prime.
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3
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OFFSET
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1,2
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COMMENTS
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Number of digits of sqrt(10)-primes (A136582).
The n such that A017934(2*n-1) is (probably) prime.
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LINKS
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Table of n, a(n) for n=1..10.
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MATHEMATICA
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rd = RealDigits[Sqrt[10], 10, 10^5][[1]]; Do[ If[ PrimeQ@ FromDigits@ Take[rd, n], Print@n], {n, 10^5}] (* Robert G. Wilson v, Jan 20 2008 *)
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PROG
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(Magma) for n in [1..10^6] do if IsPrime(Isqrt(10^(2*n-1))) then printf "%o, ", n; end if; end for; // Jason Kimberley, Sep 03 2011
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CROSSREFS
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Cf. A010467, A017934, A017934, A131581, A132153, A136582, A175733, A175734.
Sequence in context: A107615 A195605 A184096 * A307684 A141631 A172188
Adjacent sequences: A136580 A136581 A136582 * A136584 A136585 A136586
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KEYWORD
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nonn,base,more
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AUTHOR
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Lekraj Beedassy, Jan 09 2008
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EXTENSIONS
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a(6) - a(8) from Robert G. Wilson v, Jan 20 2008
Probable terms a(9) and a(10) from Jason Kimberley, Aug 19 and Sep 03 2011
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STATUS
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approved
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