Hi MHF.

I don't think anything other than the most basic number theory is taught in my country and therefore I am wondering where I can learn to solve problems such as: Find all $\displaystyle n\in\mathbb{Z}^+$ such that $\displaystyle 2^n+n\mid 8^n+n$

I'm seeing high-schoolers post these and in my country we don't learn these in high school or even college unless you major in maths.

I can't find anything on it at Khan Academy...Not sure where to look!

Thanks.