write a recursive definition for the sequence 8,6,4,2,...

write a recursive definition for the sequence 8,6,4,2,...

$$\small{ \begin{array}{rclclcl} a_1 &=& 8 \\ a_2 &=& a_1 - 2 &=& 8 - 2 &=& 6 \\ a_3 &=& a_2 - 2 &=& 6 - 2 &=& 4 \\ a_4 &=& a_3 - 2 &=& 4 - 2 &=& 2 \\ \cdots \\ \mathbf{a_n }& \mathbf{=} & \mathbf{a_{n-1}-2} \\ \\ \hline \end{array} }\\$$