Find the largest prime factor of $1+f(1)+f(2)+f(3)+\dots+f(30)$ where $f(n)=n\cdot n!$

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Here's my approach: express the sum as a telescoping series although I am not sure how to go about it I am sure it is either 29 or 31. Could someone help me?

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Notice that $$n\cdot n! = (n +1 - 1)n! = (n + 1)! - n!.$$