Impressive. Cognitive pattern recognition.
Here's the kicker though, how long did it take him to learn how to perform the test? How well do average intelligence chimps perform the same test given the same level of attention to their learning? What other tests does he excel at?
If you replaced the numbers with say, colored patches on the screen whereby each color represented the same number could he make the connection and if so, how long until he was able to do so? How many numbers can he memorize in the original test? A really tricky one, will/can he dispute the result if the computer gives him a false negative?
Given an unlimited number of typewriters, how long until he produces something as crappy as Twilight?