Representation sets for integral binary quadratic forms over the rationals

Let f be an integral binary form of discriminant d which represents n integrally. Two rational representations (r, s) and (r′, s′), with denominators prime to n, of n by f are called semiequivalent with respect to f if there is a rational automorph of f with determinant 1 and denominator m which takes (r, s) into (r′, s′) where (m, n) = 1 and m contains no factors p of d such that $\text{d}\text{p}{}^2$ is a discriminant. The number of such equivalence classes for a given f and n is sometimes finite. This number is obtained for forms with negative discriminants which have one class in each primitive genus.