Find the sum of all integers from 1to 1001.

Explanation

To find the sum of all integers from 1 to 1001, we can use the formula for the sum of the first n natural numbers. The formula is given by:

\[ S_n = \frac{n(n + 1)}{2} \]

where \( S_n \) is the sum of the first n natural numbers and n is the last number in the series.

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