A139837 Primes of the form 4x^2+4xy+23y^2.

23, 31, 47, 71, 103, 191, 199, 223, 311, 367, 383, 463, 487, 599, 631, 647, 719, 727, 751, 823, 839, 863, 911, 983, 991, 1039, 1087, 1103, 1279, 1303, 1367, 1423, 1439, 1511, 1543, 1567, 1607, 1783, 1831, 1871, 1879, 1951, 2039, 2143, 2311, 2399

Offset

1,1

Comments

Discriminant=-352. 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

The primes are congruent to {15, 23, 31, 47, 71} (mod 88).

Mathematica

QuadPrimes2[4, -4, 23, 10000] (* see A106856 *)

Prog

(Magma) [ p: p in PrimesUpTo(3000) | p mod 88 in {15, 23, 31, 47, 71}]; // Vincenzo Librandi, Jul 29 2012

Crossrefs

Sequence in context: A240886 A162587 A033216 * A145375 A086547 A054291

Adjacent sequences: A139834 A139835 A139836 * A139838 A139839 A139840

Keyword

nonn,easy

Author

T. D. Noe, May 02 2008

Status

approved