On a Class of Polynomials with Integer Coefficients

Abstract

A class P_{n,m,p}(x) of polynomials is defined. The combinatorial meaning of its coefficients is given. Chebyshev polynomials are the special cases of P_{n,m,p}(x). It is first shown that P_{n,m,p}(x) may be expressed in terms of P_{n,0,p}(x). From this we derive that P_{n,2,2}(x) may be obtain in terms of trigonometric functions, from which we obtain some of its important properties. Some questions about orthogonality are also concerned. Furthermore, it is shown that P_{n,2,2}(x) fulfills the same three terms recurrence as Chebyshev polynomials. Some others recurrences for P_{n,m,p}(x) and its coefficients are also obtained. At the end a formula for coefficients of Chebyshev polynomials of the second kind is derived.