|
%I #23 Sep 08 2022 08:45:30
%S 1,2,3,13,14,19,20,23,38,1124,7592,11755,12155,12915,14172,15500,
%T 20255,28388,184650
%N Numbers k such that 19^k - 2 is a prime.
%C No more terms through 50000. - _Ryan Propper_, Dec 04 2008
%C a(20) > 2*10^5. - _Robert Price_, Oct 22 2014
%t Do[ f = 19^n - 2; If[ PrimeQ[ f ], Print[ {n, f} ] ], {n,1,1000} ]
%o (Magma) [n: n in [0..1000] | IsPrime(19^n-2)]; // _Vincenzo Librandi_, Oct 23 2014
%Y Cf. A084714 (smallest prime of the form (2n-1)^k - 2).
%Y Cf. A128472 (smallest prime of the form (2n-1)^k - 2 for k > (2n-1)).
%Y Cf. A014224, A109080, A090669, A128455, A128457, A128458, A128459, A128461.
%K nonn,hard,more
%O 1,2
%A _Alexander Adamchuk_, Mar 14 2007
%E 1124 from _Stefan Steinerberger_, May 05 2007
%E 7592 from _Ryan Propper_, Dec 31 2007
%E Additional terms from _Ryan Propper_, Dec 04 2008
%E a(19) from _Robert Price_, Oct 22 2014
|
