Given:

To find:
The sequence and recursive expression to the given explicit expression.
Solution:
We have,

For n=1,



The value of f(1) is 12.
Similarly,
For n=2,

For n=3,

For n=4,

The required sequence is {12,14,16,18,...}.
The recursive expression of an AP is

where, d is common difference.
Here d=2,

Therefore, the recursive expression is
.