A139987 - OEIS

%I #16 Sep 08 2022 08:45:34

%S 7,127,463,487,823,967,1087,1303,1327,1423,1663,2143,2503,2647,2767,

%T 3343,3607,3823,3847,3943,4327,4447,4663,4783,5023,5167,5503,5527,

%U 5623,6007,6343,6367,6703,6967,7207,7687,8527,8647,8863,8887,10567

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

%C Discriminant=-3360. See A139827 for more information.

%H Vincenzo Librandi and Ray Chandler, <a href="/A139987/b139987.txt">Table of n, a(n) for n = 1..10000</a> [First 1000 terms from Vincenzo Librandi]

%H N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

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

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

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

%K nonn,easy

%O 1,1

%A _T. D. Noe_, May 02 2008