42 was the last remaining number below 100 which could not be expressed as the sum of three cubes - until now

Since 1954, scientists have been using computers to search for three numbers that could be cubed and summed to equal 42. Every other possible number below 100 already had a known solution, but the solution for 42 wasn't found until recently. Here's Numberphile on the significance of this discovery.

Previously: 42 is the sum of three cubes