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).