Answer
$$\frac{1}{2},\frac{1}{2},\frac{1}{2},\frac{1}{2}$$
Work Step by Step
$a_{n}=\frac{2^{n}}{2^{n+1}}=\frac{2^{n}}{2\cdot 2^{n}}=\frac{1}{2},$ so
$$a_{1}=a_{2}=a_{3}=a_{4}=\frac{1}{2}$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.