Permutations called hexagrams were used in China in the I Ching (Pinyin: Yi Jing) as early as 1000 BC.
In Greece, Plutarch wrote that Xenocrates of Chalcedon … See more

In mathematics texts it is customary to denote permutations using lowercase Greek letters. Commonly, either $${\displaystyle \alpha ,\beta ,\gamma }$$ or See more

The concept of a permutation as an ordered arrangement admits several generalizations that have been called permutations, … See more

In some applications, the elements of the set being permuted will be compared with each other. This requires that the set S has a See more

Several notations are widely used to represent permutations conveniently. Cycle notation is a popular choice, as it is compact and shows the permutation's structure clearly. … See more

The number of permutations of n distinct objects is n!.
The number of n-permutations with k disjoint cycles is the … See more

Numbering permutations
One way to represent permutations of n things is by an integer N with 0 ≤ N < n!, provided … See more