Collatz Conjecture Calculator - 3n+1 Sequence with Graph

The Collatz Conjecture Calculator generates famous mathematical sequences following 3n+1 rules for odd numbers and n/2 for even numbers. Displays interactive graph, detailed statistics, maximum value reached and complete steps table. Ideal for math students, researchers and enthusiasts wanting to explore this fascinating unsolved mathematical problem. Advanced educational tool for understanding complex numerical patterns.

Updated at: 06/28/2025

Data Input

Enter a number between 1 and 1,000,000

How the Collatz Conjecture Calculator Generates the 3n+1 Sequence

The Collatz Conjecture Calculator is an advanced educational tool designed to explore one of the most intriguing unsolved problems in mathematics. Based on the simple 3n+1 rule, it generates sequences from any positive integer and visualizes the progression using graphs and detailed statistics. This calculator is ideal for students, researchers, and enthusiasts who want to delve deeper into complex numerical patterns.

With features like a complete step-by-step table, graphical sequence display, and statistical analysis, the calculator offers an interactive way to understand how even simple mathematical rules can lead to surprisingly complex behavior. It’s a fun and powerful way to investigate mathematical logic and number theory.

What is the Collatz Conjecture?

The Collatz Conjecture, also called the 3n+1 problem, was proposed by Lothar Collatz in 1937. It starts with any positive integer and applies the following two rules:

  • If the number is even: divide it by 2

  • If the number is odd: multiply it by 3 and add 1

This process is repeated with the result from the previous step, creating a sequence that continues until it reaches 1. The conjecture asserts that every positive integer will eventually reach 1, no matter how large the starting number is.

The Rules Behind the Calculator

The Collatz Calculator automates this sequence generation using the following logic:

  • Even number rule: n = n / 2

  • Odd number rule: n = 3 * n + 1

Each new number is used as the input for the next step until the value becomes 1. The calculator records:

  • Total number of steps

  • Maximum value reached

  • Average value across all terms

  • Distribution of even and odd operations

  • Graph of the sequence progression

Example: Starting Number 12

Let’s look at the sequence for the number 12:

12 → 6 → 3 → 10 → 5 → 16 → 8 → 4 → 2 → 1

Here's what the calculator outputs:

  • Total Steps: 9

  • Max Value: 16

  • Sequence Average: 6

  • Even Operations: 7 (77.8%)

  • Odd Operations: 2 (22.2%)

  • Step to Max Value: 5

Detailed Sequence Breakdown

Each step in the Collatz sequence for 12 is shown below:

Step Current Number Type Operation Calculation Result
1 12 Even n ÷ 2 12 ÷ 2 = 6 6
2 6 Even n ÷ 2 6 ÷ 2 = 3 3
3 3 Odd 3n + 1 3 × 3 + 1 = 10 10
4 10 Even n ÷ 2 10 ÷ 2 = 5 5
5 5 Odd 3n + 1 3 × 5 + 1 = 16 16
6 16 Even n ÷ 2 16 ÷ 2 = 8 8
7 8 Even n ÷ 2 8 ÷ 2 = 4 4
8 4 Even n ÷ 2 4 ÷ 2 = 2 2
9 2 Even n ÷ 2 2 ÷ 2 = 1 1

Collatz Graph Visualization

The calculator also displays the sequence as a graph. The X-axis shows the step number, while the Y-axis represents the value at each step. This visual representation helps users understand how the values rise and fall dramatically before stabilizing at 1. Patterns like peaks, plateaus, and sudden drops become easier to observe and analyze.

Why is the Collatz Conjecture So Famous?

Despite its simple rules, the Collatz Conjecture remains unproven. Mathematicians have tested it with trillions of starting numbers, and every one has eventually reached 1. But a general proof that it holds for all positive integers still eludes experts.

Its popularity lies in the surprising complexity that arises from simple operations. It challenges our understanding of number theory and computational behavior. The unpredictability of each sequence also makes it a great case study in algorithm design, recursion, and computational mathematics.

Can I Use This for Large Numbers?

Yes, the calculator supports starting numbers up to 1,000,000. For larger inputs, the sequence may take many steps and reach very high values, which makes it even more interesting to analyze:

  • Larger numbers tend to produce longer sequences

  • Some sequences spike dramatically before eventually descending

  • Despite their length, they all appear to return to 1

This makes the tool valuable not only for basic math exercises but also for advanced experimentation and research projects.

Does the Conjecture Apply to Negative Numbers?

No, the traditional Collatz Conjecture only applies to positive integers. Applying the same rules to negative numbers leads to undefined or divergent behavior. The calculator is designed to accept only positive integers from 1 to 1,000,000 to maintain adherence to the original problem.

How Can This Help in Math Education?

The Collatz Conjecture Calculator is a powerful teaching aid because it:

  • Demonstrates how algorithms work in practice

  • Encourages curiosity and pattern recognition

  • Offers hands-on experience with iteration and conditionals

  • Helps visualize abstract math concepts through graphs

Teachers can use it to introduce recursion, complexity theory, and number systems. It also inspires students to explore unsolved problems and engage in critical thinking.