Answer:
Since there is an ending for the series with 256 this series is an infinite series.
Explanation:
The definition of a finite series is given as the sum of finite number of terms. That means it is having a finite value since we are adding a finite number of terms. An infinite series is the summation of infinite number of terms, so it does not have finite value.
Here the given example is 2 + 4 + 8 + 16 + ... 256
Since there is an ending for the series with 256 this series is a finite series.
This is an example of Geometric progression
We have

Sum of this GP is given by

Since this series have a definite value the series is a finite series.