EO Wilson, the father of behavioral biology, once said that if a lion could speak we wouldn't understand it.
I disagree, on the basis that its mind runs on an infrastructure closely related to our own, and structure and function are intimately interrelated.
But he'd be damned right in saying it about AI.
0 1 2 3 4 5 ...
0 + 0 = 0
0 + 1 = 1
1 + 1 = 2
1 + 2 = 3
I would contend that for any human-level intelligence with a written mathematical language, if the intelligence wrote down their expression of the mathematical ideas above, we would be able to identify them and understand them.
I could see this being difficult if we don’t recognize speech or writing for what it is, though. But once we do I think the meaning of mathematics at least will be self-evident with study.