perms1

returns a single permutation of the numbers 1:n

PERMS1(n,b), where n is a positive integer, creates a vector with n columns containing one permutation of the numbers from 1 to n. Input b is
a number between 1 and n! which is the index of the required permutation, such that the output of PERMS1(n,b) for b from 1 to n! is equivalent to
the output from perms(1:n). The order of the permutations is, however, different (e.g.,PERMS1(n,5) does not give the fifth row of the PERMS(1:n) output).