Block-similar polynomials
Source: IMO 2015 Shortlist, A6
July 7, 2016
algebrapolynomialIMO Shortlist
Problem Statement
Let be a fixed integer with . We say that two polynomials and with real coefficients are block-similar if for each the sequences\begin{eqnarray*}
P(2015i), P(2015i - 1), \ldots, P(2015i - 2014) & \text{and}\\
Q(2015i), Q(2015i - 1), \ldots, Q(2015i - 2014)
\end{eqnarray*}are permutations of each other.(a) Prove that there exist distinct block-similar polynomials of degree .
(b) Prove that there do not exist distinct block-similar polynomials of degree .Proposed by David Arthur, Canada