Вопрос:

Ответ:

\[a_{n} = \frac{n^{3}}{3^{n}}\]

\[a_{1} = \frac{1}{3}\]

\[a_{2} = \frac{8}{9}\]

\[a_{3} = \frac{27}{27} = 1\]

\[a_{4} = \frac{64}{81}\]