Piles of Plates (noch nicht übersetzt)
Problem 688
We stack n plates into k non-empty piles where each pile is a different size. Define f(n,k) to be the maximum number of plates possible in the smallest pile. For example when n=10 and k=3 the piles 2,3,5 is the best that can be done and so f(10,3)=2. It is impossible to divide 10 into 5 non-empty differently-sized piles and hence f(10,5)=0.
Define F(n) to be the sum of f(n,k) for all possible pile sizes k≥1. For example F(100)=275.
Further define S(N)=N∑n=1F(n). You are given S(100)=12656.
Find S(1016) giving your answer modulo 1000000007.