6. The sequence $a_{n}$ is defined as follows:

$a_{1}=1, a_{n+1}=a_{n}+\frac{2 a_{n}}{n}$, for $n \geq 1$. Find $a_{999}$.
Answer: 499500.

## School Olympiad "Conquer Sparrow Hills"

## Tasks for 7-8 Grades

## Variant 1b (Zheleznovodsk)