Polynomial Coefficient Enumeration

Let $f(x_1,...,x_k)$ be a polynomial over a field $K$. This paper considers such questions as the enumeration of the number of nonzero coefficients of $f$ or of the number of coefficients equal to $\alpha\in K^*$. For instance, if $K=\ff_q$ then a matrix formula is obtained for the number of coefficients of $f^n$ that are equal to $\alpha\in \ff_q^*$, as a function of $n$. Many additional results are obtained related to such areas as lattice path enumeration and the enumeration of integer points in convex polytopes.