MathDB
Multiply by the next one - 2^k-tuples

Source: 1961 All-Soviet Union Olympiad

August 4, 2015
combinatoricsinvarianttransformation

Problem Statement

Consider a 2k2^k-tuple of numbers (a1,a2,,a2k)(a_1,a_2,\dots,a_{2^k}) all equal to 11 or 1-1. In one step, we transform it to (a1a2,a2a3,,a2ka1)(a_1a_2,a_2a_3,\dots,a_{2^k}a_1). Prove that eventually, we will obtain a 2k2^k-tuple consisting only of 11's.