Consider the series $$\sum_{n = n_0}^{\infty}\,a_n = (x - 6)^{3} + \frac{(x - 6)^{6}}{2\cdot 2!} + \frac{(x - 6)^{9}}{4\cdot 3!} + \frac{(x - 6)^{12}}{8\cdot 4!} + \cdots$$ Find an expression for $a_n$.

$a_n =$
In the summation formula $n$ starts at $n=n_0$. What is your starting index $n_0$?
$n_0 =$
(Note that because the validity of either of your answers depends on the other, if you enter only one, both will be marked wrong.)