MathDB
UW Math Hour Olympiad 2014 Grades 8-10 #7

Source:

June 2, 2014
floor functionmodular arithmeticMath Hour Olympiad

Problem Statement

If aa is any number, a\lfloor a \rfloor is aa rounded down to the nearest integer. For example, π=\lfloor \pi \rfloor = 33. Show that the sequence
2117\lfloor \frac{2^{1}}{17} \rfloor, 2217\lfloor \frac{2^{2}}{17} \rfloor, 2317\lfloor \frac{2^{3}}{17} \rfloor, \dots
contains infinitely many odd numbers.