Solve the recurrence relation $a_{n+5}+7a_{n+4}+19a_{n+2}+16a_{n+1}+4a_n=0($Hint: $x^5+$

$\{$:$7x^4+19x^3+25x^2+16x+4=(x+1{)}^3(x+2{)}^2.)$

Solve the recurrence relation $a_{n+2}-8a_{n+1}+16a_n=0,a_0=2,a_1=4$

Solve the recurrence relation $a_{n+3}+8a_{n+2}+5a_{n+1}-50a_n=0,a_0=1,a_1=3,a_2=8$

Solve the recurrence relation $a_{n+2}+a_{n+1}+a_n=0,a_0=2,a_1=5$

Solve the recurrence relation $a_{n+2}+3a_{n+1}-18a_n=0,a_0=3,a_1=6$

Solve the recurrence relation $a_{n+2}-a_{n+1}-6a_n=0,a_0=8(-2^n)$

Solve the recurrence relation $a_{n+2}-7a_{n+1}+12a_n=2n+1$