What does n! mean?
n! (n factorial) multiplies all whole numbers from 1 up to n. So 5! = 5x4x3x2x1 = 120.
// maths › Sequences & Patterns
Factorial Spiral
Factorial growth shown as a spiral whose height is log10(n!), so you can see how explosively n! grows.
n! as a log-height spiral
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Frequently asked questions
Why does the height use log10(n!)?
Factorials grow so fast that 40! already has 48 digits. Plotting the number of digits (log10) keeps the whole spiral on screen.
Where do factorials show up?
Anywhere you count arrangements: seating plans, passwords, card shuffles, and the permutations and combinations behind probability.
How many ways can 10 people line up?
10! = 3,628,800 different orders - from just ten people.
What is 0!?
0! = 1, by definition. There is exactly one way to arrange nothing - the empty arrangement.