S. Wolfram has in has book "A New Kind of Science" listed 256 simple rules of cellular automata. Which of these rules could via iteration essentially contribute to render an input sequence more random in a certain sense?
Rule 170, for examples, simply produces a left shift and evidently is not of use in this, if I don't err. My limited computations with inputs that are more or less random seem to indicate that the majority of the 256 rules are even contraproductive in this context. How could one best proceed to clarify this issue or are there already relevant published results available?