021: Square Tower hollowed out

This tower is made up of 1^2+2^2+3^2+4^2+5^2 + ... + n^2 cubes (well it really stops with 5, but it works for any number n). Six copies of this tower fit together into a rectangular box of dimensions n,n+1 and 2n+1. This means that

1^2+2^2+3^2+4^2+5^2 + ... + n^2= n(n+1)(2n+1)/6

is a general formula for the sum for the first n squares.

If you are rich you may want to consider printing two each of these towers in different colors. Why this is a good idea will become clear when you put together a the box.