permutation
For example, there are 12 permutations of A, B, C, D taken two at a time: AB, AC, AD, BA, BC, BD, CA, CB, CD, DA, DB, DC.
Suppose that n objects are of k different kinds, with r1 alike of one kind, r2 of a second kind, and so on. Then the number of distinct permutations of the n objects equals the multinomial coefficient
where r1 + r2 + … + rk = n. For example, the number of different anagrams of the word ‘CHEESES' is 7!/3! 2!, which equals 420. Compare combination.
- Pearson's product moment correlation coefficient
- pedal curve
- pedal triangle
- Pell's equation
- pendulum
- Penrose, Roger
- Penrose tiling
- penta-
- pentagon
- pentagonal number
- pentagram
- per cent
- percentage
- percentage error
- percentile
- perfectly normal
- perfect number
- perfect square
- perigee
- perigon
- perihelion
- perimeter
- period
- periodic point
- peripheral vertex