1.设任意两个相邻的奇数分别为2n+1 和2n-1
（2n+1)²-(2n-1)²=8n
是8的倍数.
2.设三个连续整数分别为n-1 ,n ,n+1
(n--)²+n²+(n+1)²=3n²+2
3.设四个连续整数为 n,n+1,n+2,n+3
n(n+1)(n+2)(n+3)+1
= [(n+1)²-1][(n+2）²-1] +1
=[(n+1)(n+2)]²-(n+1)²-(n+2)²+1+1
=(n²+3n+2)²-2(n²+3n+2)+1
=[(n²+3n+2)-1]²
=(n²+3n+1)²