\begin{array}{ccccc}
I & -A & +\frac{1}{2}A^2 & -\frac{1}{6}A^3 & +\dots\\
 & +A & -A^2 & +\frac{1}{2}A^3 & +\dots \\
 & & +\frac{1}{2}A^2 & -\frac{1}{2}A^3 & +\dots\\
 & & & +\frac{1}{6}A^3 & +\dots\\
\end{array}