8. Given that $a_{1}, a_{2}, a_{3}, a_{4}, a_{5}$ is a permutation of $1,2,3,4,5$, and satisfies $\left|a_{i}-a_{i+1}\right| \neq 1(i=1,2,3,4)$. Then the number of permutations $a_{1}, a_{2}, a_{3}, a_{4}, a_{5}$ that meet the condition is $\qquad$.
8. 14 .

The permutations that satisfy the conditions are:
$$
\begin{array}{l}
1,3,5,2,4 ; 1,4,2,5,3 ; 2,4,1,3,5 ; \\
2,4,1,5,3 ; 2,5,3,1,4 ; 3,1,4,2,5 ; \\
3,1,5,2,4 ; 3,5,1,4,2 ; 3,5,2,4,1 ; \\
4,1,3,5,2 ; 4,2,5,1,3 ; 4,2,5,3,1 ; \\
5,2,4,1,3 ; 5,3,1,4,2 .
\end{array}
$$