what is rule 146??
Rule 146 is an elementary class 3 cellular automaton rule. I think rule 146 is interesting because although its behavior seems largely random:
... it may also be programmable via particle structures hidden in the evolution (highlighted here in red):
If rule 146 turns out to be generally programmable (i.e. if it could emulate a universal Turing machine), that would provide some (circumstantial) evidence that class 3 (random-looking) systems are generally programmable. See here for more on why this is actually kind of a deep problem.