Circular r-Permutation of n Elements

vCalc Reviewed

`P_c(n,r) = ( "n" !) / ( "r" ( "n" - "r" )!)`

`"Number of Elements"`

`"Number in permutation"`

INTRODUCTION

This equation computes the number of circular ordered arrangements of r distinct elements for a set of n elements. For example, the number of ways to arrange 5 children in a circle choosing from a group of n children.

SPECIAL CASE

The special case where n = r is the number of circular permutations of any set of n elements. See Circular Permutations for an example of this special case involving dead chickens.

author: GerryPerham

Combinatorics Calculators

`n! ` - factorial
`n! sqrt(2 pi n) (n/e)^n ` - Stirling's factorial approximation
`{::}_nC_k` - combinations
`C_r(n,k)` - combinations with repetitions
`{::}_nP_k` - permutations
`P_r(n)` - permutations with repetitions
`P_(comp)(n,2)` - Comparison permutations
`P_c (n,r)` - Circular r-Permutations of n Elements