What is another expression for the factorial of $n$ ?

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Answer 1 · 2015-06-23T10:47:43

Factorial $n$ , or $n!$ means:
Multiply all numbers from 1 up to and including $n$

Just as we have a summation sign $Sigma$ (greek letter S for sum), there is also a multiplication sign $Pi$ (greek P for product)

The expression would then be:

$n! = prod _(k=1)^n k$

Meaning: multiply all numbers $k$ , varying from $1$ to $n$ .

The $!$ -notation is more compact, but the $Pi$ -notation can be used for a lot of other purposes.

What is another expression for the factorial of nn?