Computing Shifts in 90/150 cellular automata sequences

Sequences produced by cellular automata (CA) are studied algebraically. A suitable k-cell 90/150 CA over generates a sequence of length qk−1. The temporal sequence of any cell of such a CA can be obtained by shifting the temporal sequence of any other cell. We obtain a general algorithm to compute these relative shifts. This is achieved by developing the proper algebraic framework for the study of CA sequences.