Question

Write down the sequence whose $n^{th}$ term is $\frac{3+{(-1)}^n}{3^n}$

Answer 1

Let $t_n=\frac{3+{(-1)}^n}{3^n}$
put $n=1,2,3,4,...$
so the sequence is $\frac{2}{3},\frac{4}{9},\frac{2}{27},\frac{4}{81},...$