How to solve the nonlinear recurrence which depends on $n$
We have $0 \leq a_n \leq 1$ then : $$\dfrac{n + 1}{n + 2} \leq a_{n + 1} \leq 1$$ We deduce that $a_n \to 1$.
We have $0 \leq a_n \leq 1$ then : $$\dfrac{n + 1}{n + 2} \leq a_{n + 1} \leq 1$$ We deduce that $a_n \to 1$.