IMO LongList 1967, Sweden 4
Source: IMO LongList 1967, Sweden 4
December 16, 2004
combinatoricsExtremal combinatoricscountingIMO ShortlistIMO Longlist
Problem Statement
A subset of the set of integers 0 - 99 is said to have property if it is impossible to fill a crossword-puzzle with 2 rows and 2 columns with numbers in (0 is written as 00, 1 as 01, and so on). Determine the maximal number of elements in the set with the property