But it was triangular numbers that got the ball rolling in the first place. Sign up here for the weekly Science Times newsletter.

How Much of Our Math Series Did You Retain? Try This Quiz. Test your knowledge of taxicab geometry, triangular numbers, the golden ratio and more.

Not deducible Harry and Tom have each found a 4-digit perfect square, a 3-digit perfect cube and a 3-digit triangular number that use 10 different digits, but with no leading zero. A triangular ...