`PermutationOrder`¶

Order of a permutation.

$ wo 'PermutationOrder[{1, 2, 3}]'
1

A permutation list has to be a rearrangement of 1 through n, so a repeated entry names no permutation:

$ wo 'PermutationOrder[{1, 1}]'

PermutationOrder::permlist: Invalid permutation list {1, 1}.
PermutationOrder[{1, 1}]

$ wo 'PermutationOrder[{2, 3, 1}]'
3

PermutationOrder¶