It's not very clear (make it harder to get it for free?), but isn't this TAN thing a free thing for personal noncommercial use?
https://www.mupad.org/muptan/muptan.php
It's not very clear (make it harder to get it for free?), but isn't this TAN thing a free thing for personal noncommercial use?
https://www.mupad.org/muptan/muptan.php