Test your knowledge of taxicab geometry, triangular numbers, the golden ratio and more. Credit... Supported by By Steven Strogatz “Math, Revealed,” our four-part series exploring the mathematics ...

The first four triangular numbers are 1, 3, 6 and 10, and the nth triangular number is given by the expression n(n+1)/2, so the 20th such number is 20 × 21 ÷ 2 = 210. ENIGMA is a triangular ...

At first glance, the 153 looks really meaningless. Yet, it has amazing mathematical properties. Moreover, it was not only explicitly mentioned in the Bible and, for various reasons, brings a smile to ...

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 number is one that ...