A106862 Primes of the form x^2+xy+5y^2, with x and y nonnegative.

5, 7, 11, 17, 23, 47, 61, 73, 83, 101, 131, 137, 139, 149, 157, 163, 191, 197, 199, 229, 251, 263, 271, 277, 283, 311, 347, 349, 353, 359, 367, 389, 419, 443, 457, 461, 463, 467, 499, 503, 541, 557, 571, 593, 613, 617, 619, 631, 643, 647, 653, 691, 701, 719

Offset: 1

Author

T. D. Noe, May 09 2005

Keywords

• nonn
• easy

Comments

Discriminant=-19.

Links

• Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 4000 terms from Vincenzo Librandi]
• N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Crossrefs

A106863 is the main entry for these primes. Cf. A035243.

Programs

Mathematica

QuadPrimes2[1, 1, 5, 10000] (* see A106856 *)