Multifactorial Calculator
Multifactorial Calculator
A multifactorial, or k-factorial, multiplies a number by every kth number below it instead of every single number the way an ordinary factorial does — the double factorial, for example, skips every other number. Enter a number and a degree k (2 for double factorial, 3 for triple, and so on), and this calculator computes the result instantly. It's worth noting that a double factorial n!! is not the same as applying an ordinary factorial twice, a common point of confusion.
- A multifactorial (or k-factorial) multiplies a number by every kth number below it, rather than every single number the way an ordinary factorial does — the double factorial (k=2) skips every other number.
- The double factorial n!! is not the same as applying factorial twice, (n!)! — it specifically means multiplying every other number, e.g. 8!! = 8 × 6 × 4 × 2.
- Even and odd numbers behave differently under double factorial: an even n!! ends at 2, while an odd n!! ends at 1, e.g. 9!! = 9 × 7 × 5 × 3 × 1.
How is a double factorial different from a regular factorial?
A regular factorial n! multiplies every whole number from n down to 1, while a double factorial n!! multiplies only every other number down to 1 or 2.
What is 8!! (double factorial)?
8!! = 8 × 6 × 4 × 2 = 384.
Multifactorial Calculator
A multifactorial, or k-factorial, multiplies a number by every kth number below it instead of every single number the way an ordinary factorial does — the double factorial, for example, skips every other number. Enter a number and a degree k (2 for double factorial, 3 for triple, and so on), and this calculator computes the result instantly. It's worth noting that a double factorial n!! is not the same as applying an ordinary factorial twice, a common point of confusion.
- A multifactorial (or k-factorial) multiplies a number by every kth number below it, rather than every single number the way an ordinary factorial does — the double factorial (k=2) skips every other number.
- The double factorial n!! is not the same as applying factorial twice, (n!)! — it specifically means multiplying every other number, e.g. 8!! = 8 × 6 × 4 × 2.
- Even and odd numbers behave differently under double factorial: an even n!! ends at 2, while an odd n!! ends at 1, e.g. 9!! = 9 × 7 × 5 × 3 × 1.
How is a double factorial different from a regular factorial?
A regular factorial n! multiplies every whole number from n down to 1, while a double factorial n!! multiplies only every other number down to 1 or 2.
What is 8!! (double factorial)?
8!! = 8 × 6 × 4 × 2 = 384.