MathDB
ln2*ln3*...ln n < sqrt(n!)/n

Source: VJIMC 2001 1.3

July 26, 2021
inequalities

Problem Statement

Let n2n\ge2 be a natural number. Prove that k=2nlnk<n!n.\prod_{k=2}^n\ln k<\frac{\sqrt{n!}}n.