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 A128460 Numbers n such that 19^n - 2 is a prime. 13
 1, 2, 3, 13, 14, 19, 20, 23, 38, 1124, 7592, 11755, 12155, 12915, 14172, 15500, 20255, 28388, 184650 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS No more terms through 50000. - Ryan Propper, Dec 04 2008 a(20) > 2*10^5. - Robert Price, Oct 22 2014 LINKS MATHEMATICA Do[ f = 19^n - 2; If[ PrimeQ[ f ], Print[ {n, f} ] ], {n, 1, 1000} ] PROG (MAGMA) [n: n in [0..1000] | IsPrime(19^n-2)]; // Vincenzo Librandi, Oct 23 2014 CROSSREFS Cf. A084714 = smallest prime of the form (2n-1)^k - 2, or 0 if no such number exists. Cf. A128472 = smallest prime of the form (2n-1)^k - 2 for k>(2n-1), or 0 if no such number exists. Cf. A014224, A109080, A090669, A128455, A128457, A128458, A128459, A128461. Sequence in context: A171483 A100385 A250184 * A273617 A101541 A299543 Adjacent sequences:  A128457 A128458 A128459 * A128461 A128462 A128463 KEYWORD hard,more,nonn AUTHOR Alexander Adamchuk, Mar 14 2007 EXTENSIONS 1124 from Stefan Steinerberger, May 05 2007 7592 from Ryan Propper, Dec 31 2007 Additional terms from Ryan Propper, Dec 04 2008 a(19) from Robert Price, Oct 22 2014 STATUS approved

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Last modified April 17 11:50 EDT 2021. Contains 343064 sequences. (Running on oeis4.)