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 A058025 Numbers k such that 3*13^k - 2 is prime. 1

%I

%S 1,5,11,16,59,239,299,2524,2695,7657,14028

%N Numbers k such that 3*13^k - 2 is prime.

%C The next terms are > 15000. - _Jinyuan Wang_, Feb 02 2020

%e 3(13^5) - 2 = 1113877, which is a prime number, hence 5 is in the sequence.

%e 3(13^7) - 2 = 188245549, but that is divisible by 211, hence 7 is NOT in the sequence.

%t Do[ If[ PrimeQ[ 3*13^n - 2 ], Print[ n ] ], {n, 0, 1500} ] (* RGWv *)

%t Select[Range[0, 4000], PrimeQ[(3*13^# - 2)] &] (* _Vincenzo Librandi_, Sep 28 2012 *)

%o (PARI) is(n)=ispseudoprime(3*13^n-2) \\ _Charles R Greathouse IV_, Jun 13 2017

%Y Cf. A057871 (3*13^k + 2 is prime).

%K nonn,more

%O 1,2

%A _Robert G. Wilson v_, Nov 15 2000

%E a(8)-a(9) from _Vincenzo Librandi_, Sep 28 2012

%E a(10) from _Bruno Berselli_, Sep 28 2012

%E a(11) from _Jinyuan Wang_, Feb 02 2020

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Last modified July 26 13:40 EDT 2021. Contains 346294 sequences. (Running on oeis4.)