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%I #34 Sep 08 2022 08:44:51
%S 11,19,41,59,89,131,139,179,211,241,251,281,331,379,401,409,419,449,
%T 491,499,521,569,571,601,619,641,659,691,739,761,769,809,811,859,881,
%U 929,971,1009,1019,1049,1051,1091,1129,1171,1201,1249,1259,1289,1291,1321,1361,1409,1451,1459,1481
%N Primes of the form x^2 + 10*y^2.
%D David A. Cox, "Primes of the Form x^2 + n y^2", Wiley, 1989, p. 36.
%H Vincenzo Librandi and Ray Chandler, <a href="/A033201/b033201.txt">Table of n, a(n) for n = 1..10000</a> [First 2000 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 Same as primes congruent to 1, 9, 11, or 19 mod 40. See, e.g., Cox, p. 36.
%F a(n) ~ 4n log n. - _Charles R Greathouse IV_, Nov 09 2012
%t Clear[f,lst,p,x,y]; f[x_,y_]:=x^2+10*y^2; lst={};Do[Do[p=f[x,y];If[PrimeQ[p]&&p<7212,AppendTo[lst,p]],{y,0,6!}],{x,0,6!}];Take[Union[lst],222] (* _Vladimir Joseph Stephan Orlovsky_, Aug 04 2009 *)
%t QuadPrimes2[1, 0, 10, 10000] (* see A106856 *)
%o (PARI) select(n->vecsearch([1,9,11,19],n%40), primes(100)) \\ _Charles R Greathouse IV_, Nov 09 2012
%o (Magma) [p: p in PrimesUpTo(1500) | NormEquation(10,p) eq true]; // _Bruno Berselli_, Jul 03 2016
%Y Cf. A139643.
%Y Primes in A020673.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_
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