A033216 Primes of form x^2+22*y^2.

23, 31, 47, 71, 89, 97, 103, 113, 137, 191, 199, 223, 257, 311, 313, 353, 367, 383, 401, 433, 449, 463, 487, 521, 577, 599, 617, 631, 641, 647, 719, 727, 751, 823, 839, 863, 881, 911, 929, 977, 983, 991, 1039

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 3000 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, 22, 10000] (* see A106856 *)

Formula

Primes congruent to {1, 9, 15, 23, 25, 31, 47, 49, 71, or 81} (mod 88). - T. D. Noe, Apr 29 2008 [See e.g. Cox, p. 36. - N. J. A. Sloane, May 27 2014]

a(n) ~ 4n log n. - Charles R Greathouse IV, Nov 09 2012