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Related papers: $7x\pm1$: Close Relative of Collatz Problem

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This article is based upon previous work by Sousa Ramos and his collaborators. They first prove that the existence of only one orbit associated with the Collatz conjecture is equivalent to the determinant of each matrix of a certain…

Combinatorics · Mathematics 2021-01-05 Louis Kauffman , Pedro Lopes

We show that there can be no algorithm to decide whether infinite recursively described acyclic aspherical 2-complexes are contractible. We construct such a complex that is contractible if and only if the Collatz conjecture holds.

Group Theory · Mathematics 2020-03-23 Ian J Leary

In this work the generalized Collatz problem $qn+1$ ($q$ odd) is studied. As a natural generalization of the original $3n+1$ problem, it consists of a discrete dynamical system of an arithmetical kind. Using standard methods of number…

General Mathematics · Mathematics 2021-01-08 Robert Santos

We define Collatz representations for a subset of rational numbers and prove that each real number \( x \notin (-1,1) \) can be approximated arbitrarily well by rational numbers which have only \( 2 \)'s and \( 1 \)'s in their Collatz…

General Mathematics · Mathematics 2025-04-14 Franciszek Kobus

In this paper a new conjecture equivalent to Collatz conjecture is presented. In particural, showing that (all) the solution(s) of newly introduced iterative functional equation(s) have a given property is equivalent to prove Collatz…

General Mathematics · Mathematics 2023-05-18 Giulio Masetti

Linear-constraint loops are programs whose transition relation is specified by a system of linear inequalities. The termination problem asks, given a loop, whether it admits an infinite computation. Decidability of termination remains open…

Logic in Computer Science · Computer Science 2026-05-15 Mishel Carelli

The rational covariance extension problem to determine a rational spectral density given a finite number of covariance lags can be seen as a matrix completion problem to construct an infinite-dimensional positive-definite Toeplitz matrix…

Optimization and Control · Mathematics 2012-08-31 Anders Lindquist , Giorgio Picci

The 3n+1, or Collatz problem, is one of the hardest math problems, yet still unsolved. The Collatz conjecture is to prove or disprove that the Collatz sequences COL(n) always eventually reach the number of 1, for all n belongs to N+ (all…

General Mathematics · Mathematics 2025-06-17 Chin-Long Wey

We analyze properties of the 2-adic valuations of an integer sequence that originates from an explicit evaluation of a quartic integral. We also give a combinatorial interpretation of the valuations of this sequence. Connections with the…

Number Theory · Mathematics 2007-07-17 Tewodros Amdeberhan , Dante Manna , Victor H. Moll

In this paper we are shown the following facts: The probability of increased $ A_{k}=P(T^{k} (x_{0})>T^{k-1} (x_{0})) $, and the probability of decrease $B_{k}=P(T^{k} (x_{0})<T^{k-1} (x_{0}))$ in step $ k $ of a Collataz procedure…

Number Theory · Mathematics 2017-07-04 Denis Martínez Tápanes , Jose E. Martínez Serra

The 3x+ 1 problem concerns iteration of the map on the integers given by T(n) = (3n+1)/2 if n is odd; T(n) = n/2 if n is even. The 3x+1 Conjecture asserts that for every positive integer n > 1 the forward orbit of n under iteration by T…

Number Theory · Mathematics 2011-01-12 Jeffrey C. Lagarias

This paper explores the problem of analytically approximating the orbital state for a subset of orbits in a rotating potential with oblateness and ellipticity perturbations. This is done by isolating approximate differential equations for…

Earth and Planetary Astrophysics · Physics 2022-02-02 Ethan Burnett , Hanspeter Schaub

The Collatz dynamic is known to generate a complex quiver of sequences over natural numbers which inflation propensity remains so unpredictable it could be used to generate reliable proof of work algorithms for the cryptocurrency industry.…

General Mathematics · Mathematics 2021-01-26 Alexander Rahn , Eldar Sultanow , Idriss J. Aberkane

We propose Reduced Collatz Conjecture that is equivalent to Collatz Conjecture, which states that every positive integer can return to an integer less than it, instead of 1. Reduced Collatz Conjecture is easier to explore because certain…

General Mathematics · Mathematics 2023-04-25 Wei Ren

Pairs of consecutive integers have the same height in the Collatz problem with surprising frequency. Garner gave a conjectural family of conditions for exactly when this occurs. Our main result is an infinite family of counterexamples to…

Number Theory · Mathematics 2015-12-01 Marcus Elia , Amanda Tucker

The Collatz and $abc$ conjectures, both well known and thoroughly studied, appear to be largely unrelated at first sight. We show that assuming the $abc$ conjecture true is helpful to improve the lower bound of integers initiating a…

Number Theory · Mathematics 2025-10-22 Olivier Rozier

The Collatz function is defined as C(n) = n / 2 if n is even and C(n) = 3n + 1 if n is odd. The Collatz conjecture states that every sequence generated by the Collatz function ends with the cycle (4, 2, 1) after a finite number of…

General Mathematics · Mathematics 2014-10-28 Manfred Bork

Contraction analysis uses a local criterion to prove the long-term behaviour of a dynamical system. A contraction metric is a Riemannian metric with respect to which the distance between adjacent solutions contracts. If adjacent solutions…

Dynamical Systems · Mathematics 2018-08-09 Peter Giesl

Let $A \cong k\langle X \rangle / I$ be an associative algebra. A finite word over alphabet $X$ is $I${\it-reducible} if its image in $A$ is a $k$-linear combination of length-lexicographically lesser words. An {\it obstruction} in a…

Rings and Algebras · Mathematics 2022-06-16 A. J. Kanel-Belov , I. A. Melnikov , I. V. Mitrofanov

We give new classes of examples of orbits of the diagonal group in the space of unit volume lattices in R^d for d > 2 with nice (homogeneous) orbit closures, as well as examples of orbits with explicitly computable but irregular orbit…

Dynamical Systems · Mathematics 2011-01-21 Elon Lindenstrauss , Uri Shapira