  The cumulant expansion is used to estimate generalized Lyapunov exponents of
the random-frequency harmonic oscillator. Three stochastic processes are
considered: Gaussian white noise, Ornstein-Uhlenbeck, and Poisson shot noise.
In some cases, nontrivial numerical difficulties arise. These are mostly solved
by implementing an appropriate importance-sampling Montecarlo scheme. We
analyze the relation between random-frequency oscillators and many-particle
systems with pairwise interactions like the Lennard-Jones gas.
