A happy number is defined by the following process. Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers, while those that do not end in 1 are unhappy numbers (or sad numbers).
Read more about Happy Number: Overview, Sequence Behavior, Happy Primes, Special Happy Numbers, Happy Numbers in Other Bases, Cubing The Digits Rather Than Squaring, Origin, Popular Culture, Programming Example
Famous quotes containing the words happy and/or number:
“What more is necessary to make us a happy and prosperous people? Still one thing more … a wise and frugal government, which shall restrain men from injuring one another, which shall leave them otherwise free to regulate their own pursuits of industry and improvement, and shall not take from labor the bread it has earned.”
—Thomas Jefferson (1743–1826)
“Today, almost forty years later, I grow dizzy when I recall that the number of manufactured tanks seems to have been more important to me than the vanished victims of racism.”
—Albert Speer (1905–1981)