Puzzles
Archimedes' Stomachion
Archimedes designed a square dissected into 14 oddly-shaped flat pieces, a sort of ancient tangram. He then asked a purely combinatorial question that had nothing to do with pictures: in how many distinct ways can those same 14 pieces be reassembled edge to edge back into the original square?
Reveal the answer
536 essentially different ways, counting arrangements that are just rotations or reflections of each other as one solution, or 17,152 if every rotation and reflection is counted separately. Nobody actually worked out the number until 2003, when combinatorialist Bill Cutler solved it by computer, more than 2,000 years after Archimedes posed the question in his fragmentary text on the puzzle, partly recovered from the Archimedes Palimpsest.