Shifts of k-nested sequences

We introduce a new class of subshifts of sequences, called k-graph shifts, which expresses nested constraints on k symbols instead of on two symbols like for Dyck shifts. These shifts share many properties with Markov-Dyck shifts but are generally not conjugate to them. We prove that they are conjugate to sofic-Dyck shifts. We give a computation of the multivariate zeta function for this class of shifts.