MathDB
2016 LMT Theme #8

Source:

April 11, 2016

Problem Statement

Consider the function f:[0,1)[0,1)f:[0,1)\rightarrow[0,1) defined by f(x)=2x2xf(x)=2x-\lfloor 2x\rfloor, where 2x\lfloor 2x\rfloor is the greatest integer less than or equal to 2x2x. Find the sum of all values of xx such that f17(x)=x.f^{17}(x)=x.
Proposed by Matthew Weiss