Answer
$\left\{\begin{array}{l}
a_{1}=2\\
a_{n}=7a_{n-1}
\end{array}\right.$
Work Step by Step
Note that $\left\{\begin{array}{l}
14=2\times 7\\
98=14\times 7\\
686=98\times 7\\
4802=686\times 7
\end{array}\right.\Rightarrow\quad a_{n}=7a_{n-1}$ for $n\geq 2$
(A geometric sequence is such that $a_{n}=r\cdot a_{n-1}$).
For a recursive rule, we give the information about the first term,
and a rule on how to obtain the next term from the preceding:
$\left\{\begin{array}{l}
a_{1}=2\\
a_{n}=7a_{n-1}
\end{array}\right.$
