Recursion is the best possible way of finding permutations of the string as it helps to build a clean code and also eases the debugging. 720 different permutations. 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.
You can also highlight the text in the equation and alter the font size and style as usual.
P nr represents the number of permutations of n items r at a time. N n - 1 n - 2 n - 3. By Using inbuilt Function. In general if there are n objects available from which to select and permutations P are to be formed using k of the objects at a time the number of different permutations possible is denoted by the symbol nPk.