If you had square blocks and arrange them, having a prime number of blocks means that you can't arrange them in a rectangle. So I would think (as a non-mathemat

If you had square blocks and arrange them, having a prime number of blocks means that you can't arrange them in a rectangle. So I would think (as a non-mathematician) that it shouldn't be surprising that the "corners" would appear when doing this. Or rather the non-corners.