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 A057183 Numbers n such that (17^n + 1)/18 is a prime. 15
 7, 17, 23, 47, 967, 6653, 8297, 41221, 113621, 233689, 348259 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Paul Bourdelais,A Generalized Repunit Conjecture J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002. H. Dubner and T. Granlund, Primes of the Form (b^n+1)/(b+1), J. Integer Sequences, 3 (2000), #P00.2.7. H. Lifchitz, Mersenne and Fermat primes field PROG (Prime95) PRP=1, 17, 348259, 1, 0, 0, "18" CROSSREFS Sequence in context: A115591 A265810 A026349 * A076293 A227276 A273745 Adjacent sequences:  A057180 A057181 A057182 * A057184 A057185 A057186 KEYWORD nonn AUTHOR N. J. A. Sloane, Sep 15 2000 EXTENSIONS a(8)=41221 corresponds to a probable prime discovered by Paul Bourdelais, Mar 18 2010 a(9)=113621 corresponds to a probable prime discovered by Paul Bourdelais, Sep 21 2011 a(10)=233689 corresponds to a probable prime discovered by Paul Bourdelais, Sep 03 2013 a(11)=348259 corresponds to a probable prime discovered by Paul Bourdelais, May 22 2014 STATUS approved

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