number of k which are n-squared
Source: ItaMO 2009, p6
February 23, 2012
geometryrectanglefunctioncombinatorics unsolvedcombinatorics
Problem Statement
A natural number is said -squared if by colouring the squares of a chessboard, in any manner, with different colours, we can find separate unit squares of the same colour, the centers of which are vertices of a rectangle having sides parallel to the sides of the board. Determine, in function of , the smallest natural that is -squared.