A139887 Primes of the form 2x^2+105y^2.

2, 107, 113, 137, 233, 347, 443, 617, 683, 827, 947, 953, 977, 1163, 1187, 1283, 1523, 1667, 1787, 1913, 2003, 2027, 2153, 2297, 2417, 2633, 2657, 2753, 2843, 2963, 3137, 3203, 3257, 3347, 3467, 3593, 3803, 3833, 4337, 4523, 4547, 4643

Offset: 1

Author

T. D. Noe, May 02 2008

Keywords

• nonn
• easy

Comments

Discriminant=-840. 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

[ p: p in PrimesUpTo(6000) | p mod 840 in {2, 107, 113, 137, 233, 323, 347, 443, 473, 617, 683, 737, 827}]; // Vincenzo Librandi, Jul 30 2012

Mathematica

QuadPrimes2[2, 0, 105, 10000] (* see A106856 *)

Formula

The primes are congruent to {2, 107, 113, 137, 233, 323, 347, 443, 473, 617, 683, 737, 827} (mod 840).