A140629 Primes of the form 76x^2+20xy+145y^2.

241, 409, 769, 1321, 1489, 2281, 3001, 4129, 4441, 5449, 5689, 6121, 6481, 6961, 7129, 7321, 7369, 8209, 9001, 11161, 11329, 11689, 12241, 12409, 13249, 13681, 13921, 14929, 15361, 16369, 16729, 17041, 17401, 17569, 17881, 18049, 18289

Offset: 1

Author

T. D. Noe, May 19 2008

Keywords

• nonn
• easy

Comments

Discriminant=-43680. Also primes of the form 96x^2+72xy+241y^2.

In base 12, the sequence is 181, 2X1, 541, 921, X41, 13X1, 18X1, 2481, 26X1, 31X1, 3361, 3661, 3901, 4041, 4161, 42X1, 4321, 4901, 5261, 6561, 6681, 6921, 7101, 7221, 7801, 7E01, 8081, 8781, 8X81, 9581, 9821, 9X41, X0X1, X201, X421, X541, X701, where X is 10 and E is 11. Moreover, the discriminant is -21340. - 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)

Crossrefs

Cf. A140633.

Programs

Mathematica

Union[QuadPrimes2[76, 20, 145, 10000], QuadPrimes2[76, -20, 145, 10000]] (* see A106856 *)