$$\sum_{n=1}^N n\cdot n!$$
I have tried to find a common factor of the terms but the only thing in common of all operands is $2!$.
$$\sum_{n=1}^N n\cdot n!$$
I have tried to find a common factor of the terms but the only thing in common of all operands is $2!$.
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Try telescoping with $n\cdot n!=(n+1)!-n!$.