The tenth floor has completed most of the blocks, so there are two blocks on the tenth floor. Two pieces were used.

There are (2+ 1)x2=6 blocks on the ninth floor. Four blocks are used.

There were (6+ 1)x2= 14 pieces on the eighth floor, and 8 pieces were used.

And so on.

Each floor has 30,62,126,254,510,1022,2046.

A * * * used 2046 bricks.