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Primes of the form x^2 + 54y^2.
2

%I #18 Feb 09 2017 17:21:59

%S 79,103,223,241,337,487,577,607,1033,1153,1279,1327,1399,1423,1447,

%T 1471,1489,1879,1993,2089,2113,2311,2473,2617,2647,2671,2713,2719,

%U 2767,2887,3079,3169,3271,3313,3457,3511,3559,3607,3673,3697,3793

%N Primes of the form x^2 + 54y^2.

%C Discriminant = -216. See A107132 for more information.

%H Vincenzo Librandi and Ray Chandler, <a href="/A107162/b107162.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, 54, 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)\54), if(isprime(t=w+54*y^2), listput(v,t)))); Set(v) \\ _Charles R Greathouse IV_, Feb 09 2017

%K nonn,easy

%O 1,1

%A _T. D. Noe_, May 13 2005