I wouldnt know from personal experience, but I know before my brothers actuarial/applied finance exams, he was packing heaps of notes into a 'crib sheet' as he called it, double sided, split into columns, minuscule writing. This was at macquarie
Depends mainly on the lecturer who sets the exam. In one of my maths units, there used to be a formula sheet in previous years, but as of recent the formula sheet was no longer provided.
Calculus 1 and Calculus 2 at Melbourne university both had a formula sheet for the final exam. I don't know why you are asking this now though, it would depend on the subject, and you would be able to find out for any subject pretty early on. For many maths subjects having a formula sheet would be laughable, what would you put on a formula sheet for group theory?