dx/dt = -y - z

dy/dt = x + A y + w

dz/dt = B + x z

dw/dt = -C z + D w

parameters: A = 0.25, B = 3.0, C = 0.5, D = 0.05

The step size of the fourth-order Runge-Kutta method: 0.001

Lyapunov exponents (log with base-e): 0.1120, 0.020, -0.003, -25.5515

Lyapunov dimension: 3.0052

Reference

An equation for hyperchaos

Otto Eberhard Rössler

Physics Letters A 71, 155-157 (1979)

DOI: 10.1016/0375-9601(79)90150-6