Observe that the difference of the sequence is 30. The first term is 12.
Let's use the arithmetic sequence formula
[tex]a_n=a_1+(n-1)d[/tex]Replacing the given information, we have.
[tex]\begin{gathered} a_n=12+(n-1)\cdot30 \\ a_n=12+30n-30 \\ a_n=30n-18 \end{gathered}[/tex]