MathDB
Iterative F ineq on non-negative integers

Source: MEMO 2024 I1

August 26, 2024
algebraSequencesfunctionsmonotoneconstructionFunctional inequalityfunction

Problem Statement

Let N0\mathbb{N}_0 denote the set of non-negative integers. Determine all non-negative integers kk for which there exists a function f:N0N0f: \mathbb{N}_0 \to \mathbb{N}_0 such that f(2024)=kf(2024) = k and f(f(n))f(n+1)f(n)f(f(n)) \leq f(n+1) - f(n) for all non-negative integers nn.