A139999 Primes of the form 3x^2+440y^2.

3, 443, 467, 587, 683, 947, 1307, 1523, 1787, 1907, 2003, 2027, 2267, 2843, 2963, 3083, 3323, 3347, 3947, 4283, 4547, 4643, 5003, 5483, 5867, 5987, 6323, 6803, 7043, 7187, 7283, 7307, 7547, 7643, 7907, 8123, 8243, 8363, 8387, 8627, 8867

Offset: 1

Author

T. D. Noe, May 02 2008

Keywords

• nonn
• easy

Comments

Discriminant=-5280. See A139827 for more information.

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)

Programs

Magma

[3] cat [p: p in PrimesUpTo(12000) | p mod 1320 in [203, 323, 443, 467, 587, 683, 707, 947, 1043, 1307]]; // Vincenzo Librandi, Aug 03 2012

Mathematica

QuadPrimes2[3, 0, 440, 10000] (* see A106856 *)

Formula

Except for 3, the primes are congruent to {203, 323, 443, 467, 587, 683, 707, 947, 1043, 1307} (mod 1320).