I am looking to find real quadratic fields whose Hilbert class field is abelian over $\Bbb Q$. Then I learned about genus numbers and genus field of the number field. It is enough to find a number field whose class number is equal to the genus number. In YOSHIOMI FURUTA article
I found the formula, but I have a problem with computing the order of the quotient. So I was wondering, is there a way to find genus number using Sage just like the class number.

Any help is very appreciated