Communications of the
Korean Mathematical Society CKMS

Let $K=\Bbb Q(\sqrt p)$ where $p$ is a prime of the form $a^2+4$. In [6], we obtained such $p$'s when $K$ has class number 1, 3, 5. In this paper, we extend the above result. We obtain such $p$'s having class number 7, 9, 11, 13.

Keywords: quadratic fields, Dedekind class number formula, class number

MSC numbers: 11R11, 11R29, 11Y40