A140614 - OEIS

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A140614

Primes of the form 15x^2+12xy+20y^2.

23, 47, 71, 191, 311, 383, 599, 647, 719, 839, 863, 911, 983, 1103, 1367, 1439, 1511, 1607, 1871, 2039, 2399, 2423, 2447, 2663, 2687, 2711, 2927, 3023, 3191, 3359, 3623, 3719, 3767, 4007, 4079, 4271, 4679, 4799, 4871, 4943, 5039, 5087, 5303

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OFFSET

1,1

COMMENTS

Discriminant=-1056. Also primes of the form 23x^2+12xy+36y^2.

In base 12 the sequence is 1E, 3E, 5E, 13E, 21E, 27E, 41E, 45E, 4EE, 59E, 5EE, 63E, 69E, 77E, 95E, 9EE, X5E, E1E, 10EE, 121E, 147E, 149E, 14EE, 165E, 167E, 169E, 183E, 18EE, 1X1E, 1E3E, 211E, 219E, 221E, 239E, 243E, 257E, 285E, 293E, 299E, 2X3E, 2XEE, 2E3E, 309E, where X is 10 and E is 11. Moreover, the discriminant is -740. - Walter Kehowski, May 31 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[15, 12, 20, 10000], QuadPrimes2[15, -12, 20, 10000]] (* see A106856 *)

CROSSREFS

Cf. A140633.

Sequence in context: A183010 A134517 A141376 * A001124 A139501 A292509

Adjacent sequences: A140611 A140612 A140613 * A140615 A140616 A140617

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 19 2008

STATUS

approved