OFFSET
1,1
COMMENTS
Discriminant 205.
12*a(n) has the form z^2 - 205*y^2, where z = 6*x+13*y. [Bruno Berselli, Jun 20 2014]
LINKS
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
PROG
(PARI)
fc(a, b, c, M) = {
my(t1=List(), t2);
forprime(p=2, prime(M),
t2 = qfbsolve(Qfb(a, b, c), p);
if(t2 != 0, listput(t1, p))
);
Vec(t1)
};
fc(3, 13, -3, 600)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 17 2014
STATUS
approved