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A139655
Primes of the form x^2 + 280*y^2.
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
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, Apr 29 2008
STATUS
approved