Write the first five terms of the geometric sequence defined recursively. Find the common ratio and write the n^{th} term of the sequence as a function of n. (nth term formula: a_{n}=a_{1}(r)^{n-1} ), a_{1}=16, a_{k+1}=frac{1}{2} a_{k}, a_{1}=, a_{2}=, a_{3}=, a_{4}=, a_{5}=, r=

Write the first five terms of the geometric sequence defined recursively. Find the common ratio and write the \( n^{\text {th }} \) term of the sequence \( u s \) function of \( n \). (nth term formula: \( a_{n}=a_{1}(r)^{n-1} \) ) \[ \begin{array}{l} a_{1}=16, a_{k+1}=\frac{1}{2} a_{k} \\ a_{1}=16 \\ a_{2}=8 \\ a_{3}=4 \\ a_{4}=4 \\ a_{5}=\square \\ r=2 \end{array} \]