MathDB
TOT 386 1993 Autumn A J4 diagonals of 1x1 in 8x8 table

Source:

June 12, 2024
combinatorics

Problem Statement

Diagonals of a 11 by 11 square are arranged in an 88 by 88 table (one in each 11 by 11 square). Consider the union WW of all 6464 diagonals drawn. The set WW consists of several connected pieces (two points belong to the same piece if and only if W contains a path between them). Can the number of the pieces be greater than (a) 1515, (b) 2020?
(NB Vassiliev)