A141489 Numbers n such that n^2 + n + 257 is prime.

0, 2, 3, 4, 7, 9, 10, 11, 13, 14, 17, 18, 20, 21, 23, 24, 25, 27, 28, 30, 31, 34, 37, 41, 42, 44, 48, 49, 51, 53, 56, 59, 60, 63, 65, 66, 67, 69, 70, 73, 74, 77, 79, 80, 81, 83, 88, 90, 91, 93, 94, 95, 100, 101, 104, 107, 111, 114, 115, 116, 119, 122, 125, 129, 135, 137

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

If n=0, then n^2 + n + 257 = 257 (prime).
If n=100, then n^2 + n + 257 = 10357 (prime).

Mathematica

Select[Range[0, 200], PrimeQ[#^2+#+257]&] (* Harvey P. Dale, Jun 07 2016 *)

Prog

(Magma) [n: n in [0..5000] |IsPrime(n^2+n+257)] // Vincenzo Librandi, Nov 25 2010
(PARI) isok(n) = isprime(n^2+n+257); \\ Michel Marcus, Mar 12 2017

Crossrefs

Cf. A002837, A056561, A133157, A133160.

Sequence in context: A120127 A047548 A095378 * A060253 A066276 A047340

Adjacent sequences: A141486 A141487 A141488 * A141490 A141491 A141492

Keyword

nonn

Author

Parthasarathy Nambi, Aug 09 2008

Extensions

More terms from Vincenzo Librandi, Mar 25 2010

Status

approved