MathDB
2019 no's as an arithmetic expression

Source: 2019 MEMO Problem T-4

August 30, 2019
number theorycombinatoricsmemoMEMO 2019

Problem Statement

Prove that every integer from 11 to 20192019 can be represented as an arithmetic expression consisting of up to 1717 symbols 22 and an arbitrary number of additions, subtractions, multiplications, divisions and brackets. The 22's may not be used for any other operation, for example, to form multidigit numbers (such as 222222) or powers (such as 222^2).
Valid examples: ((2×2+2)×222)×2=22    ,    (2×2×22)×(2×2+2+2+22)=42\left((2\times 2+2)\times 2-\frac{2}{2}\right)\times 2=22 \;\;, \;\; (2\times2\times 2-2)\times \left(2\times 2 +\frac{2+2+2}{2}\right)=42
Proposed by Stephan Wagner, Austria