The number of functions \( f : \{1,2,3,4\} \to \{ a \in Z \, \, |a| \le 8 \} \) satisfying \( f(n) + \frac{1}{n} f(n+1) = 1 , \forall n \in \{1,2,3\} \) is:
\( 3 \)
\( 1 \)
\( 2 \)
\( 4 \)