A139644 Primes of the form x^2 + 105*y^2.

109, 421, 541, 709, 1009, 1129, 1201, 1381, 1429, 1549, 1621, 1789, 1801, 2221, 2269, 2389, 2521, 2689, 3049, 3061, 3109, 3229, 3301, 3361, 3469, 3529, 3889, 4201, 4561, 4621, 4729, 4789, 4909, 5209, 5569, 5581, 5749, 5821, 5881, 6301

Offset

1,1

Comments

Discriminant=-420. See A139643 for more information.

The primes are congruent to {1, 109, 121, 169, 289, 361} (mod 420).

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[1, 0, 105, 10000] (* see A106856 *)

Prog

(Magma) [ p: p in PrimesUpTo(7000) | p mod 420 in {1, 109, 121, 169, 289, 361}]; // Vincenzo Librandi, Jul 28 2012
(Magma) k:=105; [p: p in PrimesUpTo(7000) | NormEquation(k, p) eq true]; // Bruno Berselli, Jun 01 2016

Crossrefs

Sequence in context: A020354 A142846 A166560 * A360490 A270249 A174339

Adjacent sequences: A139641 A139642 A139643 * A139645 A139646 A139647

Keyword

nonn,easy

Author

T. D. Noe, Apr 29 2008

Status

approved