OFFSET
1,2
COMMENTS
x^2+2xy-2y^2 is an equivalent form.
LINKS
Will Jagy, Sample output from Conway_Positive_All.cc
Will Jagy, Sample output from Conway_Positive_Prim.cc
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
MATHEMATICA
Reap[For[n = 1, n < 500, n++, r = Reduce[x^2 - 3 y^2 == n, {x, y}, Integers]; If[r =!= False, If[AnyTrue[{x, y} /. {ToRules[r /. C[1] -> 0]}, CoprimeQ @@ # &], Print[n]; Sow[n]]]]][[2, 1]] (* Jean-François Alcover, Oct 31 2016 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 11 2014
STATUS
approved