What is that interesting term?

A sequence $a_{1}$ , $a_{2}$ , $a_{3}$ .... of real number satisfies $a_{1}=2001$ and for every n greater than or equal to 1. If $a_{1}$ + $a_{2}$ + $a_{3}$ $+\cdots + a_{n-1}$ + $a_{n}$ = $n^{2}a_{n}$ .

Then compute $a_{2001}$ .