Collatz Sequence Calculator

Summary

Enter a positive integer to see its full Collatz sequence, step count, and peak value.

How it works

1. Enter any positive integer in the input field.
2. The tool applies the Collatz rule: if the number is even, divide by 2; if odd, multiply by 3 and add 1.
3. Each result becomes the next input until the value reaches 1.
4. The full sequence is displayed step-by-step with the total number of steps and the peak (maximum) value reached.

Use cases

• Explore the unsolved Collatz conjecture for specific numbers.
• Compare how many steps different numbers take to reach 1.
• Find the peak value a sequence hits before descending to 1.
• Visualize the hailstone behavior of integers for math class or research.
• Test whether large numbers eventually reach 1 (they all do, so far).

Frequently Asked Questions