Permutations of multiple numbers. In this formula n is the number of items you have to choose from and r is how many items you need to choose in a situation where repetition is allowed and order matters. The number of words is given by 4 P 3 4.
Highlight r press Ctrl or subscript.
N-factorial gives the number of permutations of n items. Want to know how many possible permutations of your name a word or a number. These permutations may or may not include repetitions which can be modified in your program code. Make a boolean array of size 26 which accounts the character being used.