Comment by hinkley

Has anyone done this work with multiple sizes of blocks? It looks to me that some of the solutions fail because (n + 1)/2 % 1 = 0.5 which puts each block ready to fall over at the slightest breeze.

Whereas a small number of blocks of 2/3 or 1/2 size allows one to sub one into the middle of a stack to adjust fulcrum points without sacrificing the extra mass needed to further stabilize lower layers. Normal bricks are half as wide as they are long and cutting one in half and turning it sideways is absolutely common. And 3:2 ratios aren’t rare. But perhaps more common in tiling.