A107197 Primes of the form 3x^2 + 28y^2.

3, 31, 103, 139, 271, 523, 619, 691, 727, 787, 811, 1063, 1123, 1399, 1447, 1531, 1567, 1699, 1783, 1867, 1879, 1987, 2239, 2287, 2467, 2551, 2659, 2803, 2887, 2971, 3163, 3307, 3331, 3391, 3463, 3559, 3583, 3631, 3967, 4219, 4591, 4639

Offset

1,1

Comments

Discriminant = -336. See A107132 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)

Mathematica

QuadPrimes2[3, 0, 28, 10000] (* see A106856 *)

Prog

(PARI) list(lim)=my(v=List(), w, t); for(x=1, sqrtint(lim\3), w=3*x^2; for(y=0, sqrtint((lim-w)\28), if(isprime(t=w+28*y^2), listput(v, t)))); Set(v) \\ Charles R Greathouse IV, Feb 10 2017

Crossrefs

Sequence in context: A077547 A104312 A326736 * A096060 A199367 A295534

Adjacent sequences: A107194 A107195 A107196 * A107198 A107199 A107200

Keyword

nonn,easy

Author

T. D. Noe, May 13 2005

Status

approved