MathDB
Putnam 1955 B5

Source:

May 24, 2022
Putnam

Problem Statement

Given an infinite sequence of 00's and 11's and a fixed integer k,k, suppose that there are no more than kk distinct blocks of kk consecutive terms. Show that the sequence is eventually periodic. (For example, the sequence 1101101010111011010101 followed by alternating 00's and 11's indefinitely, which is periodic beginning with the fifth term.)