A033245 Primes of form x^2+70*y^2.

71, 79, 151, 191, 239, 281, 359, 401, 431, 449, 569, 599, 631, 641, 751, 809, 911, 919, 991, 1009, 1031, 1129, 1201, 1289, 1409, 1439, 1471, 1481, 1759, 1801, 1831, 1871, 1999, 2039, 2081, 2111, 2129

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

References

• David A. Cox, "Primes of the Form x^2 + n y^2", Wiley, 1989.

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)

Crossrefs

Cf. A139643.

Programs

Mathematica

QuadPrimes2[1, 0, 70, 10000] (* see A106856 *)

Formula

The primes are congruent to {1, 9, 39, 71, 79, 81, 121, 151, 169, 191, 239, 249} (mod 280). - T. D. Noe, Apr 29 2008