摘要
Let n≥1 and r≥2 be integers and let d<sub>r</sub>（n） denote the number of ordered r-tuples （n<sub>1</sub>,…,n<sub>r</sub>） of natural numbers for which multiply from 1≤j≤r （n<sub>j</sub>）=n For （a,q）=1,define D<sub>r</sub>（X,q,a）=sum from n≤X n≡a（modg） （d<sub>r</sub>（n））. We are interested in finding numbers θ<sub>r</sub> as large as possible such that the following statement holds.
基金
Project supported by the National Natnral Science Foundation of China
