4. In noncommutative algebra, the term monomial refers to any arrangement of a sequence of variables from a set. For example, in a noncommutative algebraic structure on a set of four variables, {x,y,z,w} , examples of monomials of length
3 are xxx,xyx,xxy,zwy,wzx……..
a) Write a generating function for the number of monomials of length, n, in a noncommutative algebraic structure on a set of four variables.
b) Find the number of monomials of length, n, in a noncommutative algebraic structure on a set of four variables.
Recurrence Relations, Partitions, Generating Functions, Monomials and Noncommutative Algebraic Structure are investigated.