Basic math formula confusion

Question

I was studying about redundancy bits and I came across this equation and table. Now I am not sure how they get the "minimum number" redundancy bits column.

So how would they get maximum and minimum number of redundancy bits r require to correct n bits of data

Answer 1

By definition: it's the smallest integer value of r that satisfies the stated equation, 2ʳ ≥ n + r + 1.

I don't see anything about "maximum number of redundancy bits."