Lyapunov fractal

Run the logistic map x ↦ r x (1 − x) while r switches between two values a and b in a fixed pattern, and measure whether nearby starts drift apart. Inked regions are calm, where the exponent is negative; bare paper is chaos.

λ = lim 1/N Σ ln |rₙ (1 − 2xₙ)|

Fractale de Lyapunov: mathcurve lists it without an entry, so the link goes to Wikipédia