Z_n中的D.F集

On Double-free Sets of Zn

若对集S■Zn中每个元素x,均有2x∈S, 则称S为D.F(double-fee)集。设f(n)=max|S|。本文给出了计算f(n)的公式。

Let G be a group. A set S■G is called double-free (D. F) if x∈s implies 2x∈s. Let f(n)=f(Zn)=max {|s|:S is D. F of Zn} Some formulas for f(n) are given in this paper.