Donald Judd's progression sculptures are a series of wall sculptures created between 1964 [1] and the 1970s. [2] Each work is similar in form, with Judd's choice of material varying depending on the date of production. [3] Judd based each work on a simple mathematical sequence such as the Fibonacci Sequence. [4] [5] [6] He typically called the works Untitled, sometimes adding the word progression to the title. [7] [8] Judd, along with fellow artists, Dan Flavin and Mel Bochner, was interested in the minimalist notion of seriality or serial progression rather than the more classical relational method of composition. [9]