We study the persistence in a class of continuous stochastic processes that
are stationary only under integer shifts of time. We show that under certa
in conditions, the persistence of such a continuous process reduces to the
persistence of a corresponding discrete sequence obtained from the measurem
ent of the process only at integer times. We then construct a specific sequ
ence for which the persistence can be computed even though the sequence is
non-Markovian. We show that this may be considered as a limiting case of pe
rsistence in the diffusion process on a hierarchical lattice.