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MathNet 2004 — Part 01 Question 81

Math Olympiad Vault · MathNet 2004 — Part 01

Question 81

Let $a_{1}\gt 0$ and $a_{n+1}=a_{n}+\frac{n}{a_{n}}$ for $n \geq 1$. Prove that:


a) $a_{n} \geq n$ for $n \geq 2$;


b) the sequence $\left\{\frac{a_{n}}{n}\right\}_{n \geq 1}$ converges and find its limit.