See [Notes and Credit] below for a definition of the Collatz Conjecture and information about the $1,000,000 reward. Click on the green flag. Enter a positive integer. Observe the Integer window to see if the integer ends as 1. The question as to whether or not EVERY positive integer ends as 1 is unsolved. Try 27 as the positive integer to test.
German mathematics professor Lothar Collatz formed his conjecture in 1937, while a professor at the University of Hamburg. Rule: Let n = any positive integer If n is even then divide n by 2 and test for 1 If n is odd multiply n by 3, add 1, and test for 1 If n not equal to 1, repeat Conjecture: The sequence of numbers generated by the above rule is called an 'orbit'. The orbit of every n ends in 1. $1,000,000 Reward for either a proof of the Collatz conjecture or a positive integer that does not end in 1. The Clay Mathematics Institute near Boston listed seven important questions in mathematics that have never been answered and offered a $1 million reward for the solution of any one of them. The Collatz conjecture is one of the problems.Note: The Collatz Conjecture has since been removed from the list. It's still a conjecture (unproven) and will probably remain so for a long time to come. The numbers generated by the Collatz rule are also called Hailstone numbers.
