将等式进行整理得:2 2-1 2=1×2+1;
3 2-2 2=2×2+1;
4 2-3 2=2×3+1;
…
所以规律为:(n+1) 2-n 2=2n+1;
故答案为:(n+1) 2-n 2=2n+1.