(MAGMAMagma) [p: p in PrimesUpTo(3000) | p mod 60 in [19, 31]]; // Vincenzo Librandi, Jul 25 2012

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Primes of the form 4x^2 + 15y^2.

Discriminant = -240. See A107132 for more information.

Also, primes of form u^2+15v^2 where v is odd (and u is necessarily even), while A107152 (which can also be expressed as x^2+60y^2) has even v. The former is {19,31} mod 60 and the latter is {1,49} mod 60, but both can be reduced to the common congruence {1,19} mod 30. [From _- _Tito Piezas III_, Jan 01 2009]

(PARI) list(lim)=my(v=List(), t); forprime(p=19, lim, t=p%60; if(t==19||t==31, listput(v, p))); Vec(v) \\ Charles R Greathouse IV, Feb 10 2017

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Vincenzo Librandi and Ray Chandler, <a href="/A107168/b107168_1.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]

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N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

Vincenzo Librandi, <a href="/A107168/b107168.txt">Table of n, a(n) for n = 1..1000</a>

Vincenzo Librandi and Ray Chandler, <a href="/A107168/b107168_1.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]

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QuadPrimesQuadPrimes2[4, 0, 15, 10000] (* see A106856 *)

QuadPrimes[4, 0, 15, 10000] (* see A106856 *) Note: the original QuadPrimes had a bug which could sometimes give wrong answers. This sequence should be checked (unless the coefficient of xy in the quadratic form is zero, in which case QuadPrimes gives correct answers). - N. J. A. Sloane, Jun 04 2014

QuadPrimes[4, 0, 15, 10000] (* see A106856 *)

QuadPrimes[4, 0, 15, 10000] (* see A106856 *) Note: the original QuadPrimes had a bug which could sometimes give wrong answers. This sequence should be checked (unless the coefficient of xy in the quadratic form is zero, in which case QuadPrimes gives correct answers). - N. J. A. Sloane, Jun 04 2014