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Test the given series for convergence or divergence

Determine if the following series converges or diverges and justify your decision.

    \[ \sum_{n=1}^{\infty} \left( \frac{1}{n} - e^{-n^2} \right). \]


We know from the previous exercise that the series

    \[ \sum_{n=1}^{\infty} e^{-n^2} \]

converges. Hence, the series in this exercise must diverge. Otherwise, the convergence of the series in the exercise and the convergence of \sum e^{-n^2} would imply that \sum \frac{1}{n} converges, which is false. Hence, the series

    \[ \sum_{n=1}^{\infty} \left( \frac{1}{n} - e^{-n^2} \right) \]

must diverge.

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