Absolute stability region
Stable region in red.

Coefficients

\begin{align} \begin{array}{c|cccccccccc} & & & & & & & & & & \\ \frac{1}{2} & \frac{1}{2} & & & & & & & & & \\ \frac{1}{4} & \frac{1}{4} & & & & & & & & & \\ \frac{1}{2} & & & \frac{1}{2} & & & & & & & \\ \frac{3}{4} & \frac{1}{4} & & & \frac{1}{2} & & & & & & \\ \frac{1}{6} & \frac{1}{6} & & & & & & & & & \\ \frac{1}{3} & & & & & & \frac{1}{3} & & & & \\ \frac{1}{2} & \frac{1}{6} & & & & & & \frac{1}{3} & & & \\ \frac{2}{3} & & & & & & \frac{1}{3} & & \frac{1}{3} & & \\ \frac{5}{6} & \frac{1}{6} & & & & & & \frac{1}{3} & & \frac{1}{3} & \\ \hline & & \frac{1}{24} & - \frac{8}{15} & & - \frac{8}{15} & \frac{27}{40} & & \frac{27}{40} & & \frac{27}{40}\\ & & & - \frac{2}{5} & & - \frac{2}{5} & \frac{3}{5} & & \frac{3}{5} & & \frac{3}{5} \end{array}\end{align}

Properties