A139661 - OEIS

%I #22 Sep 08 2022 08:45:33

%S 409,433,457,577,769,937,1033,1249,1657,1753,1777,1801,1993,2089,2161,

%T 2473,2593,2617,2857,3001,3217,3313,3433,3673,3697,3793,3889,4129,

%U 4201,4297,4441,4513,4657,5113,5449,5521,5737,5857,5881,6073,6121

%N Primes of the form x^2 + 408*y^2.

%C Discriminant = -1632. See A139643 for more information.

%C The primes are congruent to {1, 25, 49, 121, 145, 169, 217, 361} (mod 408).

%H Vincenzo Librandi and Ray Chandler, <a href="/A139661/b139661.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)

%t QuadPrimes2[1, 0, 408, 10000] (* see A106856 *)

%o (Magma) [ p: p in PrimesUpTo(7000) | p mod 408 in {1, 25, 49, 121, 145, 169, 217, 361}]; // _Vincenzo Librandi_, Jul 29 2012

%o (Magma) */ k:=408; [p: p in PrimesUpTo(7000) | NormEquation(k, p) eq true]; // _Bruno Berselli_, Jun 01 2016

%K nonn,easy

%O 1,1

%A _T. D. Noe_, Apr 29 2008