$4$b $.$ A sequence $\{$cn$\}$

n$=0$ satisfies c$0=1,$ c$1=2,$ and cn$+1=3$cn $$

$2($cn$1)$

$2$

cn

for n $1.$

i $.$ Fill in the boxes: c$2$ ii $.$ Find the radius of convergence of the power series X

n$=0$

cnx

n

$.$