MathDB
Putnam 1997 B1

Source:

May 30, 2014
Putnamcollege contests

Problem Statement

For all reals xx define {x}\{x\} to be the difference between xx and the closest integer to xx. For each positive integer nn evaluate : Sn=m=16n1min({m6n},{m3n}) S_n=\sum_{m=1}^{6n-1}\min \left(\left\{\frac{m}{6n}\right\},\left\{\frac{m}{3n}\right\}\right)