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:
“Have you noticed when reading War and Peace the difficulties Tolstoy experienced in forcing morally wounded Bolkonsky to come into geographical and chronological contact with Natasha? It is very painful to watch the way the poor fellow is dragged and pushed and shoved in order to achieve this happy reunion.”
—Vladimir Nabokov (1899–1977)
“There is something tragic about the enormous number of young men there are in England at the present moment who start life with perfect profiles, and end by adopting some useful profession.”
—Oscar Wilde (1854–1900)