Respuesta :

Answer:

the answer is multiple of 4 I believe

Answer:

4^n-1

Step-by-step explanation:

You follow the form ar^n-1 (geometric sequence)

a is the first term

r is the ratio

We know that a is 1

and r is 4

so

1 x 4^n-1

or

4^n-1

We know that they are multiples of 4