Answer
$a_n=8(3)^{n-1}$
Work Step by Step
$ 8, 24, 72, 216, 648, 1944, . . .$
$\frac{a_2}{a_1}=\frac{24}{8}=3=r$
$ra_2=3\times24=72=a_3$
$ra_3=3\times72=216=a_4$
and so on. The sequence is geometric with common ratio $r=3$.
The $n^{th}$ term of the sequence is given by
$a_n=8r^{n-1}=8(3)^{n-1}$