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Related papers: A note on the $3x+1$ conjecture

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In this paper, a simple explanation for the Goldbach Conjecture is given. We have shown that the probability of violating the conjecture not only for the prime numbers, but also for any subset of natural numbers whose distribution is…

Number Theory · Mathematics 2023-02-07 Ameneh Farhadian , Hamid Reza Fanai

For any integer $m\ge0$, we recall that triangular numbers are those $\mathbf{T}(m)=\frac{m(m+1)}{2}$. A conjecture of Sun Zhi-Wei states that an integer $2^n\pm n$ with any $n>2$ can not be a triangular number. The motivation of this work…

Number Theory · Mathematics 2022-02-18 Wang Jia-Hui , Zhu Hui-Lin

For an integer $x$ let $t_x$ denote the triangular number $x(x+1)/2$. Following a recent work of Z. W. Sun, we show that every natural number can be written in any of the following forms with $x,y,z\in\Z$: $$x^2+3y^2+t_z, x^2+3t_y+t_z,…

Number Theory · Mathematics 2007-12-24 Song Guo , Hao Pan , Zhi-Wei Sun

The Collatz conjecture (or ``Syracuse problem'') considers recursively-defined sequences of positive integers where $n$ is succeeded by $\tfrac{n}{2}$, if $n$ is even, or $\tfrac{3n+1}{2}$, if $n$ is odd. The conjecture states that for all…

Number Theory · Mathematics 2023-04-05 Christian Hercher

We developed an algorithm that easily goes from one odd number to the next odd number in binary representation for the reduced forward Collatz map (Syracuse function). The algorithm indicates when an odd number can grow or shrink to the…

General Mathematics · Mathematics 2023-01-19 Richard Kaufman

The 1-3-5 conjecture of Z.-W. Sun states that any $n\in\mathbb N=\{0,1,2,\ldots\}$ can be written as $x^2+y^2+z^2+w^2$ with $w,x,y,z\in\mathbb N$ such that $x+3y+5z$ is a square. In this paper, via the theory of ternary quadratic forms and…

Number Theory · Mathematics 2020-03-09 Hai-Liang Wu , Zhi-Wei Sun

It is conjectured that for any fixed relatively prime positive integers $a,b$ and $c$ all greater than 1 there is at most one solution to the equation $a^x+b^y=c^z$ in positive integers $x,y$ and $z$, except for specific cases. We develop…

Number Theory · Mathematics 2025-04-15 Takafumi Miyazaki , István Pink

Let n be a positive odd integer and let p>n+1 be a prime. We mainly derive the following congruence: $$\sum_{0<i_1<...<i_n<p}(i_1/3)(-1)^{i_1}/(i_1...i_n)=0 (mod p).$$

Number Theory · Mathematics 2010-02-25 Li-Lu Zhao , Zhi-Wei Sun

Let $T$ be the map defined on $\N=\{1,2,3, ...\}$ by $T(n) = \frac{n}{2} $ if $n$ is even and by $T(n) = \frac{3n+1}{2}$ if $n$ is odd. Consider the dynamical system $(\N, 2^{\N}, T,\mu)$ where $\mu$ is the counting measure. This dynamical…

Dynamical Systems · Mathematics 2023-12-14 Idris Assani

We prove a conjecture posted in the Online Encyclopedia of Integer Sequences, namely that there are exactly five positive integers that can be written in more than one way as the sum of a nonnegative power of 2 and a nonnegative power of 3.…

Number Theory · Mathematics 2019-07-11 Douglas Edward Iannucci

In this paper we establish some new results similar to Lagrange's four-square theorem. For example, we prove that any integer $n>1$ can be written as $w(5w+1)/2+x(5x+1)/2+y(5y+1)/2+z(5z+1)/2$ with $w,x,y,z\in\mathbb Z$. Let $a$ and $b$ be…

Number Theory · Mathematics 2024-12-06 Zhi-Wei Sun

In this article, we reduce the unsolved problem of convergence of Collatz sequences to convergence of Collatz sequences of odd numbers that are divisible by 3. We give an elementary proof of the fact that a Collatz sequence does not…

General Mathematics · Mathematics 2015-10-06 Maya Mohsin Ahmed

For integers $k\ge 1$ and $m\ge 2$, let $g(k,m)$ be the least integer $n\ge 1$ such that every graph with chromatic number at least $n$ contains a $(k+1)$-connected subgraph with chromatic number at least $m$. We prove that \[ g(k,m)\le…

Combinatorics · Mathematics 2026-05-05 Achintya Raya Polavarapu

Define $\theta(x)=(x-1)/3$ if $x\geq 1$, and $\theta(x)=2x/(1-x)$ if $x<1$. We conjecture that the orbit of every positive rational number ends in 0. In particular, there does not exist any positive rational fixed point for a map in the…

Number Theory · Mathematics 2010-10-19 Mohammad Javaheri

An attempt to come closer to a resolution of the Collatz conjecture is presented. The central idea is the formation of a tree consisting of positive odd numbers with number 1 as root. Functions for generating the tree from the root are…

Number Theory · Mathematics 2018-08-20 Kerstin Andersson

Given integer $n > 0$ and $m > 1$, we call a partition of set $[n] = \{1, \dots, n\}$ {\em $m$-good} if each of the partitioning sets is of size at most $m$ and the sum of numbers in it is a power of $m$, that is, $m^t$ for some $t \geq 0$.…

Combinatorics · Mathematics 2025-08-26 Vladimir Gurvich , Mariya Naumova

We present a solution of $3x+1$ problem. For a history of this problem we refer the reader to Lagarias, Jeffrey C.

General Mathematics · Mathematics 2018-09-20 Ewa Wanda Graczyńska

For integer $g\ge 5$, we prove that any positive integer can be written as a sum of three palindromes in base $g$.

Number Theory · Mathematics 2017-06-20 Javier Cilleruelo , Florian Luca , Lewis Baxter

A multipermutation with $k$ copies each of $1\ldots n$ is Carlitz if neighbours are different. We enumerate these objects for $k=2,3,4$ and derive recurrences. In particular, we prove and improve a conjectured recurrence for $k=3$, stated…

Combinatorics · Mathematics 2017-02-20 Henrik Eriksson , Alexis Martin

We pose 100 new conjectures on representations involving primes or related things, which might interest number theorists and stimulate further research. Below are five typical examples: (i) For any positive integer $n$, there exists…

Number Theory · Mathematics 2017-12-04 Zhi-Wei Sun
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