class numbers of imaginary quadratic fields

We tabulate the ideal class numbers (http://planetmath.org/ClassNumber) $h$ of first imaginary quadratic number fields $\mathbb{Q}(\sqrt{d})$.  The table all the nine cases where the class number is 1.

The class numbers of $\mathbb{Q}(\sqrt{d})$ for the squarefree $d$’s form Sloane’s http://www.research.att.com/ njas/sequences/?q=A000924&sort=0&fmt=0&language=english&go=Searchsequence A000924.