Evaluating a finite sum in sigma notation

Substitute $i = 1, 2, 3, 4, 5$ into the expression $2^i - i$ to get the five terms: $(2^1-1), (2^2-2), (2^3-3), (2^4-4), (2^5-5)$, which simplify to $1, 2, 5, 12, 27$.

Adding these values together: $1 + 2 + 5 + 12 + 27 = 47$. So the sum evaluates to $47$.