The **3x + 1** problem, also known as the
* Collatz problem, the Syracuse problem, Kakutani's problem,
Hasse's algorithm*,
and * Ulam's problem*,
concerns the behavior of the iterates of the function which takes odd
integers **n** to **3n+1** and even integers **n** to .
The **3x+1** Conjecture asserts that, starting from any * positive* integer
**n**, repeated iteration of this function eventually produces the value 1.