A139971 Primes of the form 5x^2+104y^2.

5, 109, 149, 229, 349, 421, 461, 509, 541, 661, 709, 821, 941, 1021, 1061, 1181, 1229, 1549, 1669, 1709, 1789, 1861, 2069, 2221, 2269, 2309, 2381, 2621, 2741, 2749, 2789, 3061, 3109, 3229, 3469, 3541, 3581, 3989, 4349, 4621, 4789, 4909

Offset

1,1

Comments

Discriminant=-2080. See A139827 for more information.

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)

Formula

Except for 5, the primes are congruent to {21, 109, 141, 149, 189, 229, 301, 349, 421, 461, 501, 509} (mod 520).

Mathematica

QuadPrimes2[5, 0, 104, 10000] (* see A106856 *)

Prog

(Magma) [5] cat [ p: p in PrimesUpTo(6000) | p mod 520 in [21, 109, 141, 149, 189, 229, 301, 349, 421, 461, 501, 509]]; // Vincenzo Librandi, Aug 02 2012

Crossrefs

Sequence in context: A210904 A306990 A048564 * A305095 A128110 A316755

Adjacent sequences: A139968 A139969 A139970 * A139972 A139973 A139974

Keyword

nonn,easy

Author

T. D. Noe, May 02 2008

Status

approved