A106878 Primes of the form 3x^2+xy+3y^2.

3, 5, 7, 13, 17, 47, 73, 83, 97, 103, 157, 167, 173, 223, 227, 257, 283, 293, 307, 313, 353, 367, 383, 397, 433, 467, 503, 523, 563, 577, 587, 593, 607, 643, 647, 677, 727, 733, 773, 787, 797, 853, 857, 887, 937, 983, 997, 1013, 1063, 1097, 1123, 1153

Offset: 1

Author

T. D. Noe, May 09 2005

Keywords

• nonn
• easy

Comments

Discriminant=-35.

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

Primes in A243179.

Programs

Mathematica

Union[QuadPrimes2[3, 1, 3, 10000], QuadPrimes2[3, -1, 3, 10000]] (* see A106856 *)