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Primes of the form 5x^2+4xy+5y^2, with x and y any integer.
1

%I #20 Aug 05 2014 14:16:29

%S 5,17,41,89,101,173,257,269,293,353,461,509,521,593,677,761,773,797,

%T 857,881,929,941,1013,1049,1097,1109,1181,1193,1217,1277,1301,1361,

%U 1433,1553,1601,1613,1637,1697,1721,1889,1949,1973,2141,2273,2309

%N Primes of the form 5x^2+4xy+5y^2, with x and y any integer.

%C Discriminant=-84.

%C Primes = 5, 17, or 41 (mod 84).

%H Vincenzo Librandi and Ray Chandler, <a href="/A106972/b106972.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 Union[QuadPrimes2[5, 4, 5, 10000], QuadPrimes2[5, -4, 5, 10000]] (* see A106856 *)

%K nonn,easy

%O 1,1

%A _T. D. Noe_, May 09 2005