# What is the explicit formula for the sequence: 8, -20, 50, -125?

${a}_{n} = 8 \cdot {\left(- \frac{5}{2}\right)}^{n} , n \ge 0$
$\textcolor{w h i t e}{\text{XXX}} {a}_{0} = 8$
$\textcolor{w h i t e}{\text{XXX}} {a}_{i} = {a}_{i - 1} \cdot \left(- \frac{5}{2}\right)$