THE NUMBER OF BRICKS IN A ZIGGURAT BEN BLUMSON AND JARINAH JABBAR Abstract. The number of bricks in a ziggurat is a sum of consecutive squares. Theorem 1. The number of square bricks in a hollow ziggurat n stories high and of base width n is n2 + (n− 1)2. = + = + Figure 1 Recall that a centered square number is one that can be formed by placing one dot to serve as a center, and then by surrounding that center with square layers. Figure (2a) is a well-known visual proof that a centred square is the sum of consecutive squares (See Conway and Guy (1996, 41-2) and Deza and Deza (2012, 54)). So comparing it with figure (2b), of a ziggurat from above, provides another proof of the theorem. Date: May 21, 2020. 1 2 BEN BLUMSON AND JARINAH JABBAR (a) (b) Figure 2 1 References Conway, J. H. and Guy, R. K. (1996). The Book of Numbers, Springer, New York. Deza, E. and Deza, M. (2012). Figurate Numbers, World Scientific, Singapore. 1For comments on this paper, we thank an anonymous referee, Jeremiah Joaquin, Mike Pelczar, and Weng Hong Tang