219: How far out can you go?

A series of identical blocks.

A series of identical rectangular blocks is stacked out at their balancing points from the top down. You can show with a simple center of mass calculation the total "stick-out" distance; that is, the horizontal distance from the back of the bottom block to the back of the top block is
d = ½(1 + ½ + ⅓ + ¼ + ...)

Thanks to @fnoschese for finding these.