The sum of n terms of the sequence 1,8,27,64,125,216.... is ________? Please, provide the explanation as well on how you arrived on the result. I know the answer is {n^2x(n+1)^2}/4 but, I simply can't figure out how it came. Any help will be appreciated. If anyone finds a different answer and can prove it, even it will work. I just want to know HOW IT CAME.

Thanks to all.