MathDB

sets where each element does not divides other's sum

Source: JBMO 2011 Shortlist C5

October 14, 2017

JBMOcombinatoricsSets

Problem Statement

A set

S

of natural numbers is called good, if for each element

x \in S, x

does not divide the sum of the remaining numbers in

S

. Find the maximal possible number of elements of a good set which is a subset of the set

A = \{1,2, 3, ...,63\}