An ancient Chinese story concerns the Emperor Yu, who was standing on the bank of a river when a turtle emerged with 1 to 9 on its back in a 3 × 3 square array with numbers in each row, column and diagonal adding to the same sum, 15. This arrangement of numbers, the *Luo shu*, acquired great mystic significance and led eventually to larger such magic squares. A famous example is the 4 × 4 magic square ion Albrecht Dürer’s engraving *Melencolia I*, in which the numbers in each row, column, and man in diagonal add up to 34.

The Macau stamps show a variety of magic squares, and the values of the stamps themselves form a Luo Shu magic square.

*[Macau 2014]*