A139987 - OEIS

A139987

Primes of the form 7x^2+120y^2.

7, 127, 463, 487, 823, 967, 1087, 1303, 1327, 1423, 1663, 2143, 2503, 2647, 2767, 3343, 3607, 3823, 3847, 3943, 4327, 4447, 4663, 4783, 5023, 5167, 5503, 5527, 5623, 6007, 6343, 6367, 6703, 6967, 7207, 7687, 8527, 8647, 8863, 8887, 10567

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OFFSET

1,1

COMMENTS

Discriminant=-3360. 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

Except for 7, the primes are congruent to {127, 247, 463, 487, 583, 823} (mod 840).

MATHEMATICA

QuadPrimes2[7, 0, 120, 10000] (* see A106856 *)

PROG

(Magma) [7] cat [p: p in PrimesUpTo(11000) | p mod 840 in [127, 247, 463, 487, 583, 823]]; // Vincenzo Librandi, Aug 03 2012

CROSSREFS

Sequence in context: A084940 A246648 A308378 * A061744 A256146 A053716

Adjacent sequences: A139984 A139985 A139986 * A139988 A139989 A139990

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 02 2008

STATUS

approved