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 A136583 n such that floor(sqrt(10^(2*n-1))) is (probably) prime. 3
 1, 2, 7, 18, 33, 206, 468, 1061, 6831, 40377 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Number of digits of sqrt(10)-primes (A136582). The n such that A017934(2*n-1) is (probably) prime. LINKS Table of n, a(n) for n=1..10. MATHEMATICA 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 *) PROG (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 CROSSREFS 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 KEYWORD nonn,base,more AUTHOR Lekraj Beedassy, Jan 09 2008 EXTENSIONS 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 STATUS approved

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Last modified May 31 11:21 EDT 2023. Contains 363066 sequences. (Running on oeis4.)