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Numbers n such that n*2^1279 - 1 is prime.
2

%I #24 Sep 08 2022 08:46:14

%S 1,139,433,1563,2095,2254,2871,3751,4003,4338,4843,6015,6331,6933,

%T 7324,7345,7485,7719,7836,8070,8413,9018,9840,9898,9915,9931,10611,

%U 11215,11356,11418,11560,11740,12010,12673,13039,13056,13225,14136,14271,14380,14974,15084

%N Numbers n such that n*2^1279 - 1 is prime.

%C The exponent of 2 in the expression, 1279, is a Mersenne exponent.

%H Andrew Howroyd, <a href="/A265502/b265502.txt">Table of n, a(n) for n = 1..1000</a>

%e n = 1 is a term since 2^1279 - 1 is prime (the 15th Mersenne prime).

%t Select[Range@ 11500, PrimeQ[# 2^1279 - 1] &] (* _Michael De Vlieger_, Dec 09 2015 *)

%o (MATLAB)

%o if isprime(n*2^1279-1)

%o disp(n)

%o end

%o (PARI) is(n)=ispseudoprime(n*2^1279 - 1) \\ _Anders Hellström_, Dec 09 2015

%o (Magma) [n: n in [1..10^4] |IsPrime(n*2^1279-1)]; // _Vincenzo Librandi_, Dec 10 2015

%Y Cf. A000043, A001348, A005122.

%K nonn

%O 1,2

%A _Vardan Semerjyan_, Dec 09 2015

%E Terms a(31) and beyond from _Andrew Howroyd_, Dec 23 2019