|
%I #18 Feb 10 2017 14:40:46
%S 89,401,521,761,769,809,1009,1049,1249,1289,1361,1409,1601,1721,2081,
%T 2089,2441,2729,2801,3001,3049,3089,3121,3169,3329,3529,3881,3929,
%U 4001,4049,4201,4289,4441,4561,4649,4729,5009,5081,5209,5281,5441
%N Primes of the form x^2 + 80y^2.
%C Discriminant = -320. See A107132 for more information.
%H Vincenzo Librandi and Ray Chandler, <a href="/A107192/b107192.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, 80, 10000] (* see A106856 *)
%o (PARI) list(lim)=my(v=List(),w,t); for(x=1, sqrtint(lim\1), w=x^2; for(y=1, sqrtint((lim-w)\80), if(isprime(t=w+80*y^2), listput(v,t)))); Set(v) \\ _Charles R Greathouse IV_, Feb 10 2017
%K nonn,easy
%O 1,1
%A _T. D. Noe_, May 13 2005
|
