对于正整数k和n,设δ(k)是k的不同约数之和以,f(n)=δ(1)+δ(2)+…+δ(n).证明了存在无穷多个正整数n,可使δ(f(n))≥n(n+1).
For any positive integer k, let 8 (k) denote the sum of distinct divisors of k, and let f(n)=δ(1)+δ(2)+…+δ(n).In this paper we prove that there exist infinitely many positive integers n sarisfying δ(f(n))≥n(n+1).