Hayden is growing bacteria in two different solutions. Both populations start with a single bacteria. She records the number of bacteria in each solution every hour.

The population in solution A is modeled by the sequence An=22n, where n is the number of hours.

The population in solution B is modeled by the sequence B0=1, Bn=Bn−1+4, where n is the number of hours.

Are the sequences An and Bn functions? Why or why not?