I'm studying these algebraic numbers in the table below and have succesfully shown what i wanted with the given values I had.

The table is found in the book "The 1-2-3 of Modular Forms" by Jan Hendrik Bruinier, Gerard van der Geer, Günter Harder and Don Zagier.

I am looking for a way to calculate more numbers or/and just more values for other discriminants (-31,-35,-39,-40,-43,...).

I hope someone can help.

![Table of algebraic numbers][1] 
  [1]: https://i.sstatic.net/r9JZc.png