Solution
= Solution
Order $\nu$ requires $r(z)-e^z=O(z^{\nu+1})$ on the test equation, fixing all $\nu+1$ coefficients: $r(z)=\sum_{l=0}^{\nu}z^l/l!$.
= Solution
Order $\nu$ requires $r(z)-e^z=O(z^{\nu+1})$ on the test equation, fixing all $\nu+1$ coefficients: $r(z)=\sum_{l=0}^{\nu}z^l/l!$.