MathDB
Sum(powers of 2)

Source: May Olimpiad(Olimpiada de Mayo) 2008

February 28, 2018
combinatoricsalgorithm

Problem Statement

In a blackboard, it's written the following expression
122223242526272829210 1-2-2^2-2^3-2^4-2^5-2^6-2^7-2^8-2^9-2^{10}
We put parenthesis by different ways and then we calculate the result. For example:
12(2223)24(252627)28(29210)=403 1-2-\left(2^2-2^3\right)-2^4-\left(2^5-2^6-2^7\right)-2^8-\left( 2^9-2^{10}\right)= 403 and
1(222(2324)(252627))(2829)210=933 1-\left(2-2^2 \left(-2^3-2^4 \right)-\left(2^5-2^6-2^7\right)\right)- \left(2^8- 2^9 \right)-2^{10}= -933
How many different results can we obtain?