Answer:
The equation is 4(4)^n-1
The 4th term is 256
Step-by-step explanation:
Since you can see that you are multiplying by 4 as each term goes on, you multiply 4 by 4^n-1 because the n-1 keeps the previous term so you can multiply the previous term by that.
This may be a little confusing but the answer is correct.