The number 1888081808881 is interesting on several counts. First, it’s a prime number, evenly divisible only by itself and 1. In base 10, it’s also a palindromic number. It has the same sequence of ...

The sum of the 100th row is 100 3 = 1,000,000. If you add up the sum values of rows 1 to 8, the result is always the row number raised to the third power.

Schools sometimes teach “fact families:” triangles that connect three numbers based on their sum and differences. For example, the triangle below expresses the series of relationships: 5 + 3 = 8, 8 - ...