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%I #10 May 22 2017 12:39:09
%S 2,7,19,67,211,433,2437,2719,19531
%N Numbers n such that (46^n - 1)/45 is prime.
%C a(10) > 10^5.
%C Numbers corresponding to a(7)-a(9) are probable primes.
%C All terms are prime.
%H Harvey Dubner, <a href="http://dx.doi.org/10.1090/S0025-5718-1993-1185243-9">Generalized repunit primes</a>, Math. Comp., 61 (1993), 927-930.
%H Henri Lifchitz, <a href="http://www.primenumbers.net/Henri/us/MersFermus.htm">Mersenne and Fermat primes field</a>
%p A243279:=n->`if`(isprime((46^n - 1)/45), n, NULL); seq(A243279(n), n=1..100000); # _Wesley Ivan Hurt_, Apr 12 2014
%t Select[Prime[Range[100000]], PrimeQ[(46^# - 1)/45] &]
%o (PARI) is(n)=ispseudoprime((46^n-1)/45) \\ _Charles R Greathouse IV_, May 22 2017
%Y Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035, A127995, A127996, A127997, A127998, A127999, A098438, A128002, A128003, A128004, A128005, A240765, A242797.
%K hard,more,nonn
%O 1,1
%A _Robert Price_, Jun 02 2014
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