"Factorials"

Given the first few factorials:

1! = 1
2! = 2 x 1 = 2
3! = 3 x 2 x 1 = 6
4! = 4 x 3 x 2 x 1 = 24

What is the sum of the first 15 factorials, NOT INCLUDING 0!?


Once you realise you are summing the factors it makes this challenge a lot more manageable.

Awnser:

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