A while back we had a post about how Happy Numbers and the Spiral of Four make up a sort of binary code for all numbers in existence. We thought that was all there was to say. How wrong we were! A reader wrote in, giving me more information on how his math class made Happy Numbers the naughtiest numbers in history.

I recently posted about Happy Numbers. They're a mathematical concept with no known origin. They were first documented in the 20th century, when the child of a mathematics professor told her father that she had learned about them at school, but he was unable to trace the idea back to any point of origin. It seems they came out of nowhere.

Finding Happy Numbers isn't nearly as hard as finding their origin. Take a number - say 31 - and separate out the digits. Square each of the digits and add the squares together. You'll have a new number to repeat the cycle with. Thirty-one is 9 plus 1, which equals 10. The same process with 10 reduces down to one. Any number that, eventually, reduces down to one is a Happy Number. Any number that doesn't will get trapped into a never-ending cycle of digits, the smallest of which is four. It will loop around to four again and again, never reducing further.