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Difference between revisions of "Multifactorial number"
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A [[Factorial number]] is defined by the product | A [[Factorial number]] is defined by the product | ||
:<math>n! = 1 \cdot 2 \cdot 3 \cdots (n{-}2) \cdot (n{-}1) \cdot n</math> | :<math>n! = 1 \cdot 2 \cdot 3 \cdots (n{-}2) \cdot (n{-}1) \cdot n</math> | ||
| − | for <math>n | + | for <math>n \geq 1</math>. |
A '''Multifactorial number''' is denoted by | A '''Multifactorial number''' is denoted by | ||
Latest revision as of 14:36, 20 July 2021
Definition
A Factorial number is defined by the product
- [math]\displaystyle{ n! = 1 \cdot 2 \cdot 3 \cdots (n{-}2) \cdot (n{-}1) \cdot n }[/math]
for [math]\displaystyle{ n \geq 1 }[/math].
A Multifactorial number is denoted by
- [math]\displaystyle{ n!! = (n) \cdot (n-2) \cdot (n-4) \cdots }[/math]
- [math]\displaystyle{ n!!! = (n) \cdot (n-3) \cdot (n-6) \cdots }[/math]
and so on.
To clarify and make reading easier [math]\displaystyle{ n!!!!! }[/math] is displayed as [math]\displaystyle{ n!_5 }[/math].
