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%I #28 Dec 25 2017 20:18:25
%S 2,5,7,13,23,37,47,53,103,127,157,167,173,197,223,263,277,293,317,367,
%T 373,383,397,463,487,503,557,607,613,647,653,677,727,733,743,757,773,
%U 797,823,853,863,877,887,967,983,997,1013,1063,1087,1093,1103,1117
%N Primes of the form 2x^2 + 5y^2.
%C Discriminant = -40.
%H Ray Chandler, <a href="/A106889/b106889.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 The primes are congruent to {2, 5, 7, 13, 23, 37} (mod 40). - _T. D. Noe_, May 02 2008
%t QuadPrimes2[2, 0, 5, 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)\5), if(isprime(t=w+5*y^2), listput(v,t)))); Set(v) \\ _Charles R Greathouse IV_, Feb 09 2017
%Y Cf. A139827. Primes in A020674.
%K nonn,easy
%O 1,1
%A _T. D. Noe_, May 09 2005
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