A140625 Primes of the form 28x^2+20xy+85y^2.

157, 277, 397, 613, 733, 757, 853, 997, 1213, 1453, 1597, 2053, 2437, 2557, 2677, 2797, 3037, 3253, 3733, 3877, 4357, 4813, 4957, 5077, 5413, 5557, 6277, 6637, 6733, 6997, 7237, 7573, 8053, 8293, 8893, 9013, 9277, 9397, 9733, 9973, 10093

Offset

1,1

Comments

Discriminant=-9120. Also primes of the form 45x^2+30xy+157y^2.

In base 12, the sequence is 111, 1E1, 291, 431, 511, 531, 5E1, 6E1, 851, X11, E11, 1231, 14E1, 1591, 1671, 1751, 1911, 1X71, 21E1, 22E1, 2631, 2951, 2X51, 2E31, 3171, 3271, 3771, 3X11, 3X91, 4071, 4231, 4471, 47E1, 4971, 5191, 5271, 5451, 5531, 5771, 5931, 5X11, where X is 10 and E is 11. Moreover, the discriminant is -5340. - Walter Kehowski, Jun 01 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)

Mathematica

Union[QuadPrimes2[28, 20, 85, 10000], QuadPrimes2[28, -20, 85, 10000]] (* see A106856 *)

Crossrefs

Cf. A140633.

Sequence in context: A303094 A001837 A142581 * A142874 A346431 A234364

Adjacent sequences: A140622 A140623 A140624 * A140626 A140627 A140628

Keyword

nonn,easy

Author

T. D. Noe, May 19 2008

Status

approved