Collatz Conjecture Calculator

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Enter any positive integer. The calculator will apply the Collatz rule (divide by 2 if even, multiply by 3 and add 1 if odd) until the result reaches 1.
Steps to reach 1Long sequence
111

Total number of iterations before the sequence first lands on 1

Peak value9,232
Sequence length112
Even steps (n/2)70
Odd steps (3n+1)41
Sequence (first 12 terms)27, 82, 41, 124, 62, 31, 94, 47, 142, 71, 214, 107, ... (100 more terms)
Even steps (n/2)70
Odd steps (3n+1)41

27 reaches 1 in 111 steps with a peak of 9,232.

  • Starting from 27, the sequence takes 111 steps to reach 1.
  • The peak value is 9,232, which is 341.9x the starting number.
  • 70 even steps (halving) and 41 odd steps (3n+1) were applied.

Next stepCompare this with nearby integers to see how dramatically stopping times can vary for consecutive numbers.

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