I've just solved a combinatorics problem but my answer is stuck here: $$\sum_{i=1}^{n-1} i!(n-i)!$$ Is there any way to simplify this summation? I've thought about combinatorial proof but there's no hope. Thank you:).
2025-01-13 08:03:18.1736755398
Can we simplify this factorial summation $\sum_{i=0}^{n-1} i!(n-i)!$?
87 Views Asked by Ahmbak https://math.techqa.club/user/ahmbak/detail AtRelated Questions in COMBINATORICS
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