A139832 Primes of the form 7x^2+4xy+7y^2.

7, 43, 67, 103, 127, 163, 223, 283, 307, 367, 463, 487, 523, 547, 607, 643, 727, 787, 823, 883, 907, 967, 1063, 1087, 1123, 1303, 1327, 1423, 1447, 1483, 1543, 1567, 1627, 1663, 1723, 1747, 1783, 1867, 1987, 2083, 2143, 2203, 2287, 2347, 2383

Offset

1,1

Comments

Discriminant=-180. 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)

Formula

The primes are congruent to {7, 43} (mod 60).

Mathematica

Union[QuadPrimes2[7, 4, 7, 10000], QuadPrimes2[7, -4, 7, 10000]] (* see A106856 *)

Prog

(Magma) [ p: p in PrimesUpTo(3000) | p mod 60 in {7, 43}]; // Vincenzo Librandi, Jul 29 2012

Crossrefs

Sequence in context: A062337 A176252 A118703 * A139848 A052029 A168026

Adjacent sequences: A139829 A139830 A139831 * A139833 A139834 A139835

Keyword

nonn,easy

Author

T. D. Noe, May 02 2008

Status

approved