MathDB
Putnam 2007 B5

Source:

December 3, 2007
Putnamalgebrapolynomialfloor functioncalculusderivativelinear algebra

Problem Statement

Let k k be a positive integer. Prove that there exist polynomials P_0(n),P_1(n),\dots,P_{k\minus{}1}(n) (which may depend on k k) such that for any integer n, n, \left\lfloor\frac{n}{k}\right\rfloor^k\equal{}P_0(n)\plus{}P_1(n)\left\lfloor\frac{n}{k}\right\rfloor\plus{} \cdots\plus{}P_{k\minus{}1}(n)\left\lfloor\frac{n}{k}\right\rfloor^{k\minus{}1}. (a \lfloor a\rfloor means the largest integer a. \le a.)