The value of f(1) is 31
Solution:
Given that the sequence is defined by formula:

To find: f( 1 )
Also given that,

So, we can say,

Substitute n = 3 in given formula

Now we got, f(3) = 25
Use the similar steps to find for f(2)
Substitute n = 2 in given function

Use the similar steps to find for f(1)
Substitute n = 1 in given function

Thus value of f(1) is 31