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:
“The genius of American culture and its integrity comes from fidelity to the light. Plain as day, we say. Happy as the day is long. Early to bed, early to rise. American virtues are daylight virtues: honesty, integrity, plain speech. We say yes when we mean yes and no when we mean no, and all else comes from the evil one. America presumes innocence and even the right to happiness.”
—Richard Rodriguez (b. 1944)
“Ah, but to play man number one,
To drive the dagger in his heart,
To lay his brain upon the board
And pick the acrid colors out,
To nail his thought across the door,
Its wings spread wide to rain and snow,
To strike his living hi and ho....”
—Wallace Stevens (1879–1955)