A139998 - OEIS

A139998

Primes of the form 31x^2+22xy+31y^2.

31, 199, 271, 439, 1039, 1231, 1279, 1399, 1879, 1951, 2239, 2551, 2719, 2791, 3079, 3391, 3559, 3631, 3919, 4231, 4591, 4639, 4759, 5431, 5479, 6079, 6151, 6271, 6991, 7159, 7591, 7759, 7951, 8431, 8599, 8839, 9439, 9511, 9631, 9679

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Discriminant=-3360. See A139827 for more information.

Also primes of the forms 31x^2+18xy+111y^2 and 31x^2+10xy+55y^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)

FORMULA

The primes are congruent to {31, 199, 271, 391, 439, 559} (mod 840).

MATHEMATICA

Union[QuadPrimes2[31, 22, 31, 10000], QuadPrimes2[31, -22, 31, 10000]] (* see A106856 *)

PROG

(Magma) [p: p in PrimesUpTo(12000) | p mod 840 in [31, 199, 271, 391, 439, 559]]; // Vincenzo Librandi, Aug 03 2012

CROSSREFS

Sequence in context: A100689 A055816 A274501 * A142654 A137657 A228220

Adjacent sequences: A139995 A139996 A139997 * A139999 A140000 A140001

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 02 2008

STATUS

approved