by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
Induction: \n\n n=5⟹32>25 which is obviously true. \n\n Assume it holds for n=k \n\n 2k>k2 \n\n Now since k>4,(k−1)2>2⟹k2>2k+1⟹2k2>(k+1)2 \n\n From our inductive hypothesis, 2k>k2⟹2k+1>2k2>(k+1)2 from our result above. \n\n Therefore, 2n>n2 for all n>4