A Device for Generating Fields of Even Class Number
Harvey Cohn · Proceedings of the American Mathematical Society · 1956
The device in question is typefied by the following two theorems: Quadratic theorem.If for integral g{>0), m, k{>\) k2 -1 (1) « =-+ g, g and f = m2-\-4 is square-free, then the quadratic field of discriminant f has even class number.