# Questions tagged [collatz-conjecture]

For questions about the iterated map $n \to 3n+1$ if $n$ is odd and $n \to \frac n2$ if $n$ is even, and its generalizations.

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### Knight moves on a Triangular Arrangement of the First Iteration of the Collatz Function

This is related to the Collatz function which can be written $$T(n) = \begin{cases} n/2 &\text{if } n \equiv 0 \pmod{2}\\ 3n+1 & \text{if } n\equiv 1 \pmod{2} .\end{cases}$$ All I did was ...
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### Is there a number that using the rules of Collatz conjecture's variation $3n-1$ doesn't get to $1, 7$ or $17$?

The rules are simple: Take any number $n$. If $n$ is even divide it by two, if $n$ is odd triple it and subtract one. Repeat indefinitely. (Note that this is a variation, in the original Collatz ...
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### Simplified variant of Collatz conjecture.

I came across the Collatz conjecture. So apparently the idea is to see if all prime factors of a number can be 'annihilated' by successive steps of either removing a factor of two, if n is even or in ...
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### Collatz Patterns

I have seen documentation on the $4K+1$ pattern, but as of yet I have seen nothing on the $64K+35$ pattern or the $262144K+184471$ pattern. Is there anywhere I can read up on these? I created the ...
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### What facts are known about the hypothetical smallest divergent integer in the collatz conjecture?

If there is a divergent integer in the collatz conjecture then there must be a smallest divergent number by the WOP. We can observe some properties of this number such as it must be odd because if it ...
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### What level of mathematics do I need to study the Collatz Conjecture?

I recently came across the Collatz Conjecture and I'm really intrigued by its tautological simplicity and complexity. I'm under no illusions that I can make any progress with a proof for it but I ...
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### Will the Collatz conjecture work for $m \cdot (n)+1$ for an odd number, where m is any odd number?

The Collatz conjecture asks you to: When '$n$' is the given number, 1) Divide $n$ by $2$ if the number is even. 2) Do $3n+1$ when the number is odd, and you will reach the series $4->2->1$. ...
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### How does $3n+1$ change the proximity of $n$ to a power of two?

This is part of an attempt to prove Collatz's conjecture. I proved a modification of Collatz's conjecture, where instead of $3n+1$ if $n$ is odd, you do $n+1$. In Collatz's conjecture, if you get to a ...
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### On solving the Collatz conjecture

This method may be kinda inefficient as solving each step may require $O(n!)$ computational time, but for $n$ Collatz operations isn't it possible to disprove the existence of a cycle of $n$ ...
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### Hailstone collatz max sequence length upper bound of $260.5+x^{.43}$?

Let the Collatz function be defined as if $x$ even $c(x)=x/2$, if $x$ odd then $c(x)=3x+1$ over the naturals. Each operation is defined as a step. For example $3$ goes $(3,10,5,16,8,4,2,1)$ and takes ...
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### Collatz Conjecture, sufficient to show odd numbers reach $1$?

The famous conjecture: Let $$f(n) = \begin{cases} n/2 & \quad \text{if } n \text{ is even}\\ 3n+1 & \quad \text{if } n \text{ is odd}\\ \end{cases}$$ The Collatz Conjecture ...
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### Do all primes occur in some sequence associated with the Collatz conjecture?

Let $f(n) = \begin{cases} n/2, & \text{if$n$is even} \\ 3n+1, & \text{if$n$is odd} \end{cases}$ For an arbitrary prime $p$ are there some start value $x_0$ such that $p = x_k$ for some ...
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### Can it be proven that Collatz numbers cannot repeat?

One potential counterexample of the Collatz conjecture would be if there was a number that looped back to itself. Of course, this would still not prove the conjecture because some sequences could ...
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### How to prove equally likely steps of the Hailstone sequence (collatz sequence)

Consider the condensed collatz conjecture if $x$ odd then $f(x)=(3x+1)/2$: if $x$ even $f(x) = x/2$: Continue until $x = 1$ or find an $x$ in the natural numbers that will not hit $1$. The equation ...
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### Closed form of iterated function

It can be easily calculated that performing the operation $(3x+1)$ on a number m, k times yields the result $(3^k)(m)+(3^k -1)/2$ I want to calculate a closed formula for performing the related ...
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### hailstone sequence of perfect squares (collatz conjecture)

The Collatz conjecture states: Take any positive integer $n$. If $n$ is even, divide it by $2$ to get $n/2$. If $n$ is odd, multiply it by $3$ and add $1$ to obtain $3n + 1$. Repeat the process ...
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### Don't know what this expanding periodic-ish function is

I plotted a function $c(x)$, which returns $3x + 1$ if $x$ is odd, and $x/2$ if $x$ is even. It's the Collatz conjecture. I get this interesting function. I don't know what it's called, so I can't ...
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### How many steps to reach 1? (Collatz Conjecture) [closed]

Is there some sort of algorithmic process or equation to determine the number of steps required for any given integer n to reach 1 in the Collatz Conjecture without having to actually perform a ...
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### Is this a proof for the Collatz conjecture

For this problem, which I believe is still unsolved, I was wondering what is wrong with this proof I thought of (probably is wrong somehow) https://en.wikipedia.org/wiki/Collatz_conjecture So my ...
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### Is the Collatz function piecewise linear?

I read somewhere that the Collatz function $\mathbb Z \rightarrow \mathbb Z$: $$\text{Collatz}(x) = \begin{cases} x/2 &&x \; \mathrm{even} \\ 3x+1 &&x \; \mathrm{odd}\end{cases}$$ is ...
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### Besides the $3x + 1$ problem, for which similar problems are still unresolved regarding trayectory?

Generalize the $3x + 1$ problem as $cx \pm 1$, where $c$ is a positive odd integer and $x$ is a positive integer iterated through the function as far as possible to discover a cycle. If $x$ is even, ...
Assuming Goldbach's conjecture, let's denote $r_{0}(n)$ for any integer $n$ greater than $1$ the smallest non negative integer $r$ such that both $n+r$ and $n-r$ are primes. Let $f$ be the map $m\... 1answer 726 views ### Uses of “Collatz induction”? The Collatz conjecture is equivalent to the following "induction principle": If$P(0) \land P(1) \land (\forall{x} P(3 \cdot x + 2) \implies P(2 \cdot x + 1)) \land (\forall x P(x) \implies P(2 \cdot ...
Most people think that the Collatz conjecture is true, but I think that I can prove the opposite. Let's make two functions, $f(x)$ and $g(x)$. $f(x) =$ The amount of numbers that can be solved in x ...