best_approx(n::Number, I::AbstractRange, J::AbstractRange)
best_approx(n::Number, I_max::Integer, J::Integer)

For a given number $n$, given two ranges $I$ and $J$, finds the nicest solution such that

\[i^j \approx n \text{ for } i \in I, j \in j.\]

Returns (i, j) as a tuple.

Given integers $I_{\text{max}}$ and $J_{\text{max}}$ it will assume the ranges between $I = \left\lbrack 1, I_{\text{max}}\right\rbrack$ and $J = \left\lbrack 1, J_{\text{max}}\right\rbrack$.

best_approx(n::Number, R::AbstractRange)
best_approx(n::Number, R_max::Integer)

For a given number $n$, given a range $R$, finds the "nicest" solution of $m$ such that

\[r^m \approx n \text{ for } r \in R.\]

Returns (r, m) as a tuple.

Given an integer $R_{\text{max}}$ it will assume the range between $R = \left\lbrack 1, R_{\text{max}}\right\rbrack$.