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%I #11 Jun 20 2014 04:42:04
%S 31,41,61,251,349,379,389,401,419,431,449,461,491,619,631,739,769,811,
%T 821,829,1009,1061,1171,1181,1229,1231,1279,1289,1321,1361,1451,1471,
%U 1499,1601,1699,1721,1759,1861,2081,2131,2239,2339,2341,2411,2551,2579,2591,2789
%N Primes represented by the indefinite quadratic form -x^2+13xy+9y^2.
%C Discriminant 205.
%C 4*a(n) has the form 205*y^2 - z^2, where z = 2*x-13*y. [_Bruno Berselli_, Jun 20 2014]
%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)
%o (PARI)
%o fc(a,b,c,M) = {
%o my(t1=List(),t2);
%o forprime(p=2,prime(M),
%o t2 = qfbsolve(Qfb(a,b,c),p);
%o if(t2 != 0, listput(t1,p))
%o );
%o Vec(t1)
%o };
%o fc(-1,13,9,600)
%Y Primes in A243703.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Jun 17 2014