One of my favorite topics in Discrete Math is Finite State Machines (FSM). We study deterministic machines without feedback, which can be used to
* recognize certain types of strings
* perform certain tasks (e.g. binary addition).
This particular example of an FSM recognizes input that include multiples of 3 0s (including none). If the nth input represents a complete multiple of 3 0s, then the output will be 1; otherwise 0.
