Let
\[ N = \sum_{a_1 = 0}^2 \sum_{a_2 = 0}^{a_1} \sum_{a_3 = 0}^{a_2} \dots \sum_{a_{2011} = 0}^{a_{2010}} \left [ \prod_{n=1}^{2011} a_n \right ]. \]

Find the remainder when $N$ is divided by 1000.

Let's think step by step and output the final answer within \boxed{}.
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