A265498 Numbers n such that n*2^521 - 1 is prime.

1, 1362, 1756, 1905, 2337, 2707, 2902, 2997, 3487, 3492, 3787, 3879, 4045, 4266, 4374, 4680, 5106, 5691, 5766, 6321, 6352, 6585, 6819, 7056, 7099, 7162, 7470, 7627, 8055, 8061, 8121, 8499, 8511, 8785, 8865, 9432, 9636, 9876, 10116, 10389, 10629, 10752, 11262

Offset: 1

Author

Vardan Semerjyan, Dec 09 2015

Keywords

• nonn
• easy

Comments

The exponent of 2 in the expression, 521, is a Mersenne exponent.

Examples

			n = 1 is a term since 2^521-1 is prime (13th Mersenne prime).
		

Crossrefs

Cf. A000043, A001348, A005122.

Programs

MATLAB

if isprime(n*2^521-1)
disp(n)
end

Magma

[n: n in [1..2*10^4] |IsPrime(n*2^521-1)]; // Vincenzo Librandi, Dec 10 2015

Mathematica

Select[Range@ 12050, PrimeQ[# 2^521 - 1] &] (* Michael De Vlieger, Dec 09 2015 *)

PARI

is(n) = ispseudoprime(n*2^521 - 1); \\ Altug Alkan, Dec 10 2015