MathDB

2

Part of 1988 Kurschak Competition

Problems(1)

A set of triplets from {1,2,...,n}

Source: Kürschák 1988, problem 2

7/20/2014
Set T⊂{1,2,…,n}3T\subset\{1,2,\dots,n\}^3 has the property that for any two triplets (a,b,c)(a,b,c) and (x,y,z)(x,y,z) in TT, we have a<b<ca<b<c, and also, we know that at most one of the equalities a=xa=x, b=yb=y, c=zc=z holds. Maximize ∣T∣|T|.
combinatorics unsolvedcombinatorics