|
%I #20 Dec 15 2023 20:07:34
%S 2,43,61,331,389,419,587,691,1093,1109,1187,1237,1637,1723,2069,2179,
%T 2221,2269,2309,2557,2699,2837,3253,3259,3491,3533,3571,3581,3821,
%U 3907,4093,4259,4283,4451,4603,4651,4733,5051,5189,5387,5531,5653
%N Primes of the form 2x^2 + 43y^2.
%C Discriminant = -344. See A107132 for more information.
%H Vincenzo Librandi and Ray Chandler, <a href="/A107200/b107200.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[2, 0, 43, 10000] (* see A106856 *)
%o (PARI) list(lim)=my(v=List(),w,t); for(x=0, sqrtint(lim\2), w=2*x^2; for(y=0, sqrtint((lim-w)\43), if(isprime(t=w+43*y^2), listput(v,t)))); Set(v) \\ _Charles R Greathouse IV_, Feb 10 2017
%Y Cf. A107132.
%K nonn,easy
%O 1,1
%A _T. D. Noe_, May 13 2005
|
