Source: 1998 National High School Mathematics League, Exam Two, Problem 3
March 9, 2020
number theory
Problem Statement
For positive integers a,n, define Fn(a)=q+r, where a=qn+r (q,r are nonnegative integers, 0≤q<n). Find the largest integer A, there are positive integers n1,n2,n3,n4,n5,n6, for all positive integer a≤A, Fn6(Fn5(Fn4(Fn3(Fn2(Fn1(a))))))=1.