9. In an arithmetic sequence $\left\{a_{n}\right\}$ with a common difference not equal to 0, $a_{4}=10$, and $a_{3}, a_{6}, a_{10}$ form a geometric sequence, then the general term formula of the sequence $\left\{a_{n}\right\}$ is $\qquad$.
Let the common difference of the sequence $\left\{a_{n}\right\}$ be $d$, then $\left(a_{4}+2 d\right)^{2}=\left(a_{4}-d\right)\left(a_{4}+6 d\right) \Rightarrow 10 d^{2}=a_{4} d \Rightarrow d=1$, so $a_{n}=n+6$.