 A pair of positive integers $(m,n)$ is called [b][i]'steakmaker'[/i][/b] if they maintain the equation 1 + 2$^m$ = n$^2$. For which values of m and n, the pair $(m,n)$ are steakmaker, find the sum of $mn$
1. We start with the given equation for a pair of positive integers \((m, n)\):
   \[
   1 + 2^m = n^2
   \]
2. We need to find pairs \((m, n)\) that satisfy this equation. To do this, we can rearrange the equation:
   \[
   2^m = n^2 - 1
   \]
   Notice that \(n^2 - 1\) can be factored as:
   \[
   n^2 - 1 = (n - 1)(n + 1)
   \]
   Therefore, we have:
   \[
   2^m = (n - 1)(n + 1)
   \]
3. Since \(2^m\) is a power of 2, both \((n - 1)\) and \((n + 1)\) must be powers of 2. Let:
   \[
   n - 1 = 2^a \quad \text{and} \quad n + 1 = 2^b
   \]
   where \(a\) and \(b\) are non-negative integers with \(a < b\). Then:
   \[
   2^b - 2^a = 2
   \]
4. Simplifying the above equation, we get:
   \[
   2^a (2^{b-a} - 1) = 2
   \]
   Since \(2^a\) is a power of 2, the only way this equation holds is if \(2^a = 2\) and \(2^{b-a} - 1 = 1\). Thus:
   \[
   2^a = 2 \implies a = 1
   \]
   and
   \[
   2^{b-a} - 1 = 1 \implies 2^{b-1} = 2 \implies b - 1 = 1 \implies b = 2
   \]
5. Substituting \(a = 1\) and \(b = 2\) back into the expressions for \(n\):
   \[
   n - 1 = 2^1 = 2 \implies n = 3
   \]
   \[
   n + 1 = 2^2 = 4 \implies n = 3
   \]
6. Now, substituting \(n = 3\) back into the original equation to find \(m\):
   \[
   1 + 2^m = 3^2 = 9 \implies 2^m = 8 \implies m = 3
   \]
7. Therefore, the pair \((m, n) = (3, 3)\) is a solution. The sum of \(mn\) is:
   \[
   mn = 3 \times 3 = 9
   \]

The final answer is \(\boxed{9}\).