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%I #22 Sep 08 2022 08:45:18
%S 41,89,241,281,401,409,449,521,569,601,641,761,769,809,881,929,1009,
%T 1049,1129,1201,1249,1289,1321,1361,1409,1481,1489,1601,1609,1721,
%U 1801,1889,2081,2089,2129,2161,2281,2441,2521,2609,2689,2729,2801
%N Primes of the form x^2 + 40y^2.
%C Discriminant = -160. See A107132 for more information.
%H Vincenzo Librandi and Ray Chandler, <a href="/A107145/b107145.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 {1, 9} (mod 40). - _T. D. Noe_, Apr 29 2008
%t QuadPrimes2[1, 0, 40, 10000] (* see A106856 *)
%o (Magma) [ p: p in PrimesUpTo(3000) | p mod 40 in {1, 9} ]; // _Vincenzo Librandi_, Jul 24 2012
%o (PARI) list(lim)=my(v=List(),t); forprime(p=41,lim, t=p%40; if(t==1||t==9, listput(v,p))); Vec(v) \\ _Charles R Greathouse IV_, Feb 09 2017
%Y Cf. A139643.
%K nonn,easy
%O 1,1
%A _T. D. Noe_, May 13 2005
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