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arXiv 1503.06906math.NTmath.CO
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无等比数列的小间隔序列II

Geometric Progression-Free Sequences with Small Gaps II

Xiaoyu He

摘要:

当$k$至少为$3$的常数时,正整数序列$S$称为$k$ -GP-free,如果它不包含非平凡的$k$ -项几何级数。Beiglbök,Bergelson,Hindman和Strauss首先研究了具有有界间隙的$ $ $k$ -GP-free序列的存在性。在以前的论文中,作者通过构建具有大小为$O(\exp(6\log n/\log\log n))$的空位的$6$-GP-free序列$S$给出了这个问题的部分答案。我们将这个问题推广到允许间隙函数$k$增长到无穷大,并问:对于哪对函数$(h,k)$,存在间隙大小为$O(h)$的$k$-GP-free序列?我们发现,只要$(k(n)-3)\log h(n)\log\log h(n)\ge4\log2\cdot\log n$和$h,k$满足温和的增长条件,这样的序列存在。

英文摘要:

When $k$ is a constant at least $3$, a sequence $S$ of positive integers is called $k$-GP-free if it contains no nontrivial $k$-term geometric progressions. Beiglbök, Bergelson, Hindman and Strauss first studied the existence of a $ $$k$-GP-free sequence with bounded gaps. In a previous paper the author gave a partial answer to this question by constructing a $6$-GP-free sequence $S$ with gaps of size $O(\exp(6\log n/\log\log n))$. We generalize this problem to allow the gap function $k$ to grow to infinity, and ask: for which pairs of functions $(h,k)$ do there exist $k$-GP-free sequences with gaps of size $O(h)$? We show that whenever $(k(n)-3)\log h(n)\log\log h(n)\ge4\log2\cdot\log n$ and $h,k$ satisfy mild growth conditions, such a sequence exists.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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