Problem 42937. Project Euler: Problem 14, Longest Collatz sequence
The following iterative sequence is defined for the set of positive integers:
n → n/2 (n is even) n → 3n + 1 (n is odd)
Using the rule above and starting with 13, we generate the following sequence:
13 → 40 → 20 → 10 → 5 → 16 → 8 → 4 → 2 → 1 It can be seen that this sequence (starting at 13 and finishing at 1) contains 10 terms. Although it has not been proved yet (Collatz Problem), it is thought that all starting numbers finish at 1.
Which starting number, under N, produces the longest chain?
NOTE: Once the chain starts the terms are allowed to go above N.
Solution Stats
Problem Comments
-
1 Comment
See my problem 42673: Longest Collatz Sequence
Solution Comments
Show commentsProblem Recent Solvers21
Suggested Problems
-
Is my wife right? Now with even more wrong husband
1322 Solvers
-
11254 Solvers
-
Rotate input square matrix 90 degrees CCW without rot90
616 Solvers
-
307 Solvers
-
142 Solvers
More from this Author2
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!