MathDB
IOQM 2023-24 P-21

Source:

September 3, 2023
function

Problem Statement

For nNn \in \mathbb{N}, consider non-negative valued functions ff on {1,2,,n}\{1,2, \cdots , n\} satisfying f(i)f(j)f(i) \geqslant f(j) for i>ji>j and i=1n(i+f(i))=2023.\sum_{i=1}^{n} (i+ f(i))=2023. Choose nn such that i=1nf(i)\sum_{i=1}^{n} f(i) is at least. How many such functions exist in that case?