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A006034
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Numbers n such that (17^n-1)/16 is prime.
(Formerly M2415)
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12
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3, 5, 7, 11, 47, 71, 419, 4799, 35149, 54919, 74509, 1990523
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OFFSET
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1,1
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COMMENTS
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No others for any n less than 8447. - Julien Peter Benney (jpbenney(AT)ftml.net), Aug 15 2004
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REFERENCES
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Ribenboim, Paulo; "The Book Of Prime Number Records"; published 1989 by Springer-Verlag; pages 350-354.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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Table of n, a(n) for n=1..12.
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930.
H. Dubner, Generalized repunit primes, Math. Comp., 61 (1993), 927-930. [Annotated scanned copy]
H. Lifchitz, Mersenne and Fermat primes field
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MATHEMATICA
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lst={}; Do[If[PrimeQ[(17^n-1)/16], Print[n]; AppendTo[lst, n]], {n, 10^5}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 21 2008 *)
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PROG
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(PARI) is(n)=isprime((17^n-1)/16) \\ Charles R Greathouse IV, Apr 28 2015
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CROSSREFS
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Sequence in context: A242944 A137355 A147143 * A288716 A083840 A088051
Adjacent sequences: A006031 A006032 A006033 * A006035 A006036 A006037
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KEYWORD
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hard,nonn,more
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AUTHOR
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N. J. A. Sloane
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EXTENSIONS
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a(9)=35149 & a(10)=54919 are probable primes discovered by Paul Bourdelais, Mar 08 2010
a(11)=74509 is a probable prime discovered by Paul Bourdelais, Mar 10 2010
a(12)=1990523 corresponds to a probable prime discovered by Paul Bourdelais, Aug 03 2020
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STATUS
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approved
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