Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**JonathanS****Member**- Registered: 2011-10-14
- Posts: 2

Hello, I visited mathsisfun.com/combinatorics/combinations-permutations-calculator.html and would like to get the source code for the combination where order matters and no repeats.

The one that is n!/(n-r)!

I would be using it for a program I am making that outputs all possible tetrahedral molecules.

Thanks!

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,535

Hi JonathanS;

There is some confusion here.

like to get the source code for the combination where order matters and no repeats.

When order matters it is called a permutation.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**JonathanS****Member**- Registered: 2011-10-14
- Posts: 2

ah k, got to google some algorithms for permutations, thanks!

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,535

Hi JonathanS;

You should be able to find many of them.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline