A139991 Primes of the form 15x^2+56y^2.

71, 191, 239, 359, 431, 599, 911, 1031, 1439, 1871, 2039, 2111, 2591, 2711, 2879, 3119, 3719, 4271, 4391, 4799, 5231, 5279, 5399, 5471, 5639, 6311, 6791, 6911, 6959, 7079, 7151, 7919, 8831, 8999, 9311, 9431, 9479, 9839, 10151, 10271, 11159

Offset: 1

Author

T. D. Noe, May 02 2008

Keywords

• nonn
• easy

Comments

Discriminant=-3360. See A139827 for more information.

Also primes of the forms 39x^2+12xy+44y^2 and 36x^2+12xy+71y^2. See A140633. - T. D. Noe, May 19 2008

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)

Programs

Magma

[p: p in PrimesUpTo(12000) | p mod 840 in [71, 191, 239, 359, 431, 599]]; // Vincenzo Librandi, Aug 03 2012

Mathematica

QuadPrimes2[15, 0, 56, 10000] (* see A106856 *)

Formula

The primes are congruent to {71, 191, 239, 359, 431, 599} (mod 840).