Dynamical maps in the semimajor axis–eccentricity plane in terms of the MEGNO fast indicator. Each point in the maps was integrated for 10 Myr, equivalent to more than 20,000 orbits of planet HR 8799b. Stable systems are confined to ﹩\langle Y\rangle \simeq 2﹩ (blue), and yellow marks strongly unstable configurations that are typically self-disrupting in less than 1 Myr. The star symbols mark the nominal osculating elements in the initial condition in Table 1 for each planet in subsequent panels. The resolution of each map is 800 × 480 pixels.