6.6.18 Combinatorics

Problem: Find the sequence \( \left\{a_{n}\right\} \), that satisfies the recurrence relation \( 2 \cdot a_{n+2}+10 \cdot a_{n+1}+8 \cdot a_{n}=0 \) and the initial conditions \( a_{1}=3, a_{2}=9 \).