A139899 Primes of the form 5x^2+48y^2.

5, 53, 173, 197, 293, 317, 557, 653, 677, 773, 797, 1013, 1277, 1373, 1493, 1613, 1637, 1733, 1877, 1973, 1997, 2213, 2237, 2333, 2357, 2477, 2693, 2837, 2957, 3413, 3533, 3557, 3677, 3797, 3917, 4013, 4133, 4157, 4253, 4373, 4397, 4493

Offset: 1

Author

T. D. Noe, May 02 2008

Keywords

• nonn
• easy

Comments

Discriminant=-960. 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

[5] cat [ p: p in PrimesUpTo(6000) | p mod 120 in [53, 77]]; // Vincenzo Librandi, Jul 31 2012

Mathematica

QuadPrimes2[5, 0, 48, 10000] (* see A106856 *)

Formula

Except for 5, the primes are congruent to {53, 77} (mod 120).