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:
“A name with meaning could bring up a child,
Taking the child out of the parents’ hands.
Better a meaningless name, I should say,
As leaving more to nature and happy chance.
Name children some names and see what you do.”
—Robert Frost (1874–1963)
“He is the greatest artist who has embodied, in the sum of his works, the greatest number of the greatest ideas.”
—John Ruskin (1819–1900)