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PermutationsAsCycles ​

Every permutation of {1,…,n}\{1, …, n\} in cycle notation, fixed points kept, listed by cycle type.

PermutationsAsCycles(n)every permutation of {1,…,n}\{1, …, n\} as a cycle decomposition, by cycle type
Typed signatures
TypePackageApplies
(integer<0..>) -> indexed_collection<cycle_decomposition>combinatoricsalways

Domain: Collections

Details
  • The same permutations as SymmetricGroup, in another order: by cycle type, in IntegerPartitions' order (the nn-cycles first, the identity last), then by the canonical cycle form, lexicographically. The order is our choice, not something cycle notation implies.
  • Each element is a CycleDecomposition, so every permutation statistic answers on it.

Maps

Into and out of CycleDecomposition, called as CombinatorialMap(x, "Name"). Properties are the laws we state and what FindStat records.

From CycleDecomposition

  • PermutationCycleDecomposition → PermutationinverseThe permutation a cycle decomposition describes.

To CycleDecomposition

  • CycleDecompositionPermutation → CycleDecompositioninverseA permutation in cycle notation, fixed points kept: each cycle from its least point, cycles in order of those points.

Examples

1 more kept as data, checked against the oracles
Basic #

4!4!

live ↗
InCount(PermutationsAsCycles(4))\mathrm{Count}(\mathrm{PermutationsAsCycles}(4))Out2424

The first is an nn-cycle; the identity comes last

live ↗
InPermutationsAsCycles(4)[1]\mathrm{PermutationsAsCycles}(4)[1]OutCycleDecomposition⁡([[1,2,3,4]]){\operatorname{CycleDecomposition}}([[1, 2, 3, 4]])
Statistics #

A permutation statistic, through the conversion: the Stirling numbers of the first kind

live ↗
InTally(CombinatorialStat(PermutationsAsCycles(4),CycleCount))\mathrm{Tally}(\mathrm{CombinatorialStat}(\mathrm{PermutationsAsCycles}(4), \text{CycleCount}))OutTuple⁡([1,2,3,4],[6,11,6,1])\operatorname{Tuple}(\bigl\lbrack1, 2, 3, 4\bigr\rbrack,\bigl\lbrack6, 11, 6, 1\bigr\rbrack)
About
Examples4
CrosswalkOEIS

See also: SymmetricGroup, CycleDecomposition, IntegerPartitions