Solve$\backslash$:the$\backslash$:recurrence$\backslash$:relation$\backslash$:a$\_$n$=4\backslash$cdot $\backslash$:a$\_\{$n$-1\}=3\backslash$cdot $\backslash$:a$\_\{$n$-2\}\backslash$:for$\backslash$:the$\backslash$:initial$\backslash$:conditions$\backslash$:a$\_1=2,\backslash$:a$\_2=5.$