For the series ∑n=1∞n3n\sum_{n=1}^{\infty} \frac{n}{3^n}∑n=1∞3nn, compute the ratio test limit limn→∞an+1an\lim_{n \to \infty} \frac{a_{n+1}}{a_n}limn→∞anan+1.
000
13\frac{1}{3}31
111
333