A139655 Primes of the form x^2 + 280*y^2.

281, 401, 449, 569, 641, 809, 1009, 1129, 1201, 1289, 1409, 1481, 1801, 2081, 2129, 2521, 2689, 2801, 2969, 3049, 3089, 3329, 3361, 3529, 3761, 3889, 3929, 4001, 4201, 4481, 4561, 4649, 4729, 5009, 5209, 5441, 5569, 5849, 5881, 6329, 6449

Offset

1,1

Comments

Discriminant=-1120. See A139643 for more information.

The primes are congruent to {1, 9, 81, 121, 169, 249} (mod 280).

Links

Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 (first 1000 terms from Vincenzo Librandi).

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Mathematica

QuadPrimes2[1, 0, 280, 10000] (* see A106856 *)

Prog

(Magma) [ p: p in PrimesUpTo(7000) | p mod 280 in {1, 9, 81, 121, 169, 249}]; // Vincenzo Librandi, Jul 29 2012
(Magma) k:=280; [p: p in PrimesUpTo(7000) | NormEquation(k, p) eq true]; // Bruno Berselli, Jun 01 2016

Crossrefs

Sequence in context: A308456 A175145 A142444 * A161190 A178033 A098677

Adjacent sequences: A139652 A139653 A139654 * A139656 A139657 A139658

Keyword

nonn,easy

Author

T. D. Noe, Apr 29 2008

Status

approved