1³+2³=9=(1+2)^21³ +2³+3³=36=(1+2+3)^2=6^2
1³+.10³=(1+2+3+4...+10)^2=55^2
1³+2³ +3³.+n³ =(1+2+...n)^2=[(1+n)n/2]^2=(1+n)^2n^2/4