Answer
See below.
Work Step by Step
We need to substitute $1, 2, 3,$ and $4$ for $n$ into the given equation to find the first four terms.
$c_1=\dfrac{2^{(1-1)}}{4}=\dfrac{1}{4}$
$c_2=\dfrac{2^{(2-1)}}{4}=\dfrac{1}{2}$
$c_3=\dfrac{2^{(3-1)}}{4}=\dfrac{2^2}{4}=1$
$c_3=\dfrac{2^{(4-1)}}{4}=\dfrac{2^3}{4}=2$
We see that the the next term is equal to $2$ times the current term and this implies that the sequence is geometric with a common ratio of $2$
