Whether arguing about including zero or wondering what comes after infinity, mathematicians have always been fascinated with counting things. We consider a simple example of counting in mathematics, the Erdös number. This number was created as a tribute to one of the most prolific modern mathematicians. How appropriate, then, to borrow this notion in honor of two mathematicians whose work has counted just as much, if not more.
Jonathan Duncan came to Walla Walla College as a mathematics major in 1992. There he developed an overwhelming curiosity about what went on behind the closed door of the mathematics faculty meeting. This prompted him to attend Indiana University in pursuit of the credentials necessary to attend those meetings. The privilege of collaborating with Tom and Ken over the past decade has been well worth the work it took to get through that door.