MathDB
A rather unfair team leader

Source: Tuymaada 2005, Day 1, Problem 2

July 30, 2005
algebrapolynomialalgebra unsolved

Problem Statement

Six members of the team of Fatalia for the International Mathematical Olympiad are selected from 1313 candidates. At the TST the candidates got a1,a2,,a13a_1,a_2, \ldots, a_{13} points with aiaja_i \neq a_j if iji \neq j.
The team leader has already 66 candidates and now wants to see them and nobody other in the team. With that end in view he constructs a polynomial P(x)P(x) and finds the creative potential of each candidate by the formula ci=P(ai)c_i = P(a_i).
For what minimum nn can he always find a polynomial P(x)P(x) of degree not exceeding nn such that the creative potential of all 66 candidates is strictly more than that of the 77 others?
Proposed by F. Petrov, K. Sukhov