关于数论函数δ(n)的一个问题

A problem on the arithmetic function δ(n)

对于正整数n,设δ(n)是n的不同约数之和.本文证明了:存在无穷多个正整数n可使δ(n)>(δ(n-1)δ(n+1))^(1/2).

For any positive integer n,let δ（n） denote the sum of distinct divisors of n.This paper proved that there exist infinitely many positive integers n satisfying δ（n）δ（n-1）δ（n＋1）.