Absolute stability region
Stable region in red.

Coefficients

\begin{align} \begin{array}{c|ccccccc} & & & & & & & \\ \frac{1}{2} & \frac{1}{2} & & & & & & \\ \frac{1}{3} & \frac{1}{3} & & & & & & \\ \frac{2}{3} & \frac{1}{3} & & \frac{1}{3} & & & & \\ \frac{1}{4} & \frac{1}{4} & & & & & & \\ \frac{1}{2} & \frac{1}{4} & & & & \frac{1}{4} & & \\ \frac{3}{4} & \frac{1}{4} & & & & \frac{1}{4} & \frac{1}{4} & \\ \hline & & 2 & - \frac{9}{2} & - \frac{9}{2} & \frac{8}{3} & \frac{8}{3} & \frac{8}{3}\\ & & 1 & -3 & -3 & 2 & 2 & 2 \end{array}\end{align}

Properties