A106970 Primes of the form x^2-xy+21y^2, with x and y nonnegative.

23, 41, 83, 131, 193, 199, 227, 229, 277, 293, 397, 401, 521, 557, 607, 659, 701, 739, 751, 773, 787, 811, 983, 1013, 1019, 1061, 1117, 1231, 1289, 1409, 1423, 1427, 1447, 1511, 1523, 1531, 1553, 1667, 1669, 1693, 1709, 1723, 1747, 1753, 1847

Offset

1,1

Comments

Discriminant=-83.

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, -1, 21, 10000] (* see A106856 *)

Crossrefs

Sequence in context: A163635 A083444 A153037 * A155702 A114379 A345099

Adjacent sequences: A106967 A106968 A106969 * A106971 A106972 A106973

Keyword

nonn,easy

Author

T. D. Noe, May 09 2005

Status

approved