共 109 个问题,第 3/6 页
Seeking Guidance for Pure Mathematics
I had currently passed 10th grade. I want to go in pure mathematics and research and publish paper in that field (especially Number Theory) please tell me roadmap and the books to follow one after one. Please Guide me.
Does OEIS sequence A252502 contain all even numbers which are totients and all odd numbers $n$ with $n-1$ totients?
For even number $n$, if $n$ is not a totient (i.e. not in the range of Euler totient function), then $n$ is not in OEIS sequence A252502, but if $n$ is a totient, must be $n$ in A252502? For odd number $n$, if $n-1$ is not a totient (i.e. not in the range of Euler totient function), then $n$ is...
Problem Similar to Erdős Problem 252
Erdős Problem 252:(https://www.erdosproblems.com/252) Let $k\geqslant 1$ and $\sigma_{k}(n):= \sum_{d|n} d^{k}$. Is $\displaystyle \sum_{n=1}^{\infty} \frac{\sigma_{k}(n)}{n!}$ irrational? Currently this problem is open for $k \geqslant 5$. I am considering a different version of this problem...
Conjecture: A binomial sum congruence for Fibonacci
In this related question, @Gerry Myerson asked if the conjecture fails for composites. Upon examining for composites, I found a pattern for module $n^2$ instead of $n^3$ in the linked original question. I have verified these conjectures for $n \le 5 \times 10^6$. Can they be proved or disproved....
Conjecture: Binomial sum congruence on Fibonacci and prime numbers
My experimental data suggests that the following binomial sum congruence involving primes and Fibonacci numbers hold. I have experimentally verified them for all primes $\le 1.5 \times 10^6$. Can they be proved or disproved? Conjecture 1. Let $p$ be a prime, $ p\equiv 1 \text{ or } 19 \pmod{30}....
Does $x_1^8+x_2^8+x_3^8+x_4^4 = y_1^8+y_2^8+y_3^8+y_4^4$ have infinitely many solutions?
I. Question Consider the following independent and symmetric mixed equations, $\quad x_1^8+x_2^8+x_3^4 = y_1^8+y_2^8+y_3^4$ $\quad x_1^8+x_2^8+x_3^4+x_4^4 = y_1^8+y_2^8+y_3^4+y_4^4$ $\quad x_1^8+x_2^8+x_3^8+x_4^4 = y_1^8+y_2^8+y_3^8+y_4^4$ $\quad x_1^8+x_2^8+x_3^8+x_4^8+x_5^4 =...
Non-trivial solutions to $x^4 - Ny^4 = 1$ where $N = a^4 + b^4 + c^4$
I am investigating the Diophantine equation $$x^4 - Ny^4 = 1$$ where $N$ can be expressed as a sum of three fourth powers: $$N = a^4 + b^4 + c^4$$ for integers $a, b, c$. Background: I see some from $\mathrm{A356496}$ for squarefree integers $k$ such that $x^4 - ky^2 = 1$ has a nontrivial...
Primes as $X-Y$ with $\gcd(X,Y)=1$ and $\operatorname{rad}(XY)$ equal to the product of all primes below $p$ — is this known?
Title: Primes as $X-Y$ with $\gcd(X,Y)=1$ and $\operatorname{rad}(XY)$ equal to the product of all primes below $p$ — is this known? While experimenting with multiplicative decompositions of primes, I arrived at the following question. I would like to know whether it is already in the...
A continued fraction for the reciprocal of Gauss's constant
I found the following infinite continued fraction: $$ \frac{1}{G} = \frac1{(2\pi)^{-3/2}\,\Gamma^2(1/4)} = \cfrac{4}{1+\cfrac{5}{1+\cfrac{6}{1+\cfrac{9}{1+\cfrac{8}{1+\cfrac{13}{\ddots}}}}}} $$ where $G$ denotes Gauss's constant, and the partial numerators are defined by interweaving sequences...
Why does repeatedly prepending a fixed bit-block converge the Collatz step-count difference to the block's own length?
I've been experimenting with a self-similar construction for the Collatz map (the $n \to n/2$ / $n \to 3n+1$ function) and found a pattern I can partially — but not fully — explain. I'd appreciate a sanity check and any pointers to relevant literature. Construction. Fix an odd integer $x$ with...
Why does the Euclidean algorithm outperform prime factorization for finding the GCD of large integers?
While creating quantitative aptitude problems for management entrance exam preparation, I noticed that the Euclidean algorithm is almost always preferred over prime factorization for computing the greatest common divisor.
Solving system of congruences involving powers
I am in the middle of a problem which needs showing that the following system of congruences has finite number of solutions. I have verified up to some extent through sage that this has only two solutions for $(q, r)$ (with $q<r$) namely $(11, 17)$ and $(23, 103)$. The system of congruences is...
Algebraic tracking of the Collatz trajectory for the family of numbers $n = 3^x + 2^x$
Is it possible to know how many steps are left to reach 1 knowing only x? The main idea is: when we analyze numbers of the form $n = 3^x + 2^x$ (for $x \ge 1$), we can track the Collatz trajectory using algebra instead of doing it number by number. Following the rules (if it is odd, multiply by...
Geometric structure of the $E(n).O(n)$ state space for the digit map $f(n)=(E(n).O(n))²$.
Consider the digit dynamical system $$ f(n)=\bigl(E(n)\,O(n)\bigr)^2, $$ where $E(n)$ and $O(n)$ denote the sums of the even and odd decimal digits of a positive integer $n$, respectively. The state of an integer may be represented by the ordered pair $$ (E(n),O(n)). $$ I plotted all attainable...
A bridge from modular quadratic congruences $x^2 \equiv 1^2 \pmod n$ to generalized Pell equations $X^2 - nY^2 = 1 - n$
I have been analyzing the problem of integer factorization by looking at non-trivial square roots of unity modulo $n$. Starting directly from the quadratic congruence $x^2 \equiv 1^2 \pmod n$, I derived a specific parameterization that maps the problem onto a generalized Pell equation of the...
Natural generalization of Euler-type constants
Let $$ \gamma=\lim_{x\to\infty}\left(\sum_{n=1}^x \frac1n-\log x\right) = 0.57721... $$ be Euler’s constant, and let $$ M=\lim_{x\to\infty}\left(\sum_{p \text{ prime}}^{p\le x}\frac1p-\log\log x\right)=0.26149... $$ be Mertens’ constant. These are two examples of reciprocal sums with (iterated-)...
On special equal sums $x_1^n+x_2^n +\dots + x_n^n = (x_n+1)^n$
Let all terms be positive. There are infinitely many solutions to, $$a^2+b^2 = (b+1)^2$$ $$a^3+b^3+c^3 = (c+1)^3$$ like the well-known $3^2+4^2 = 5^2$ and $3^3+4^3+5^3 = 6^3$. However, this has versions for higher degrees. For $4$th powers by Jaroslaw Wroblewski, $$178^4 + 1345^4 + 10400^4 +...
Generalization of IMO 2026 problem 1 to Triplets(k=3 ) proving invariance and Termination
In the recent IMO 2026 Problem 1, a blackboard game is played where two active integers $m, n > 1$ are repeatedly selected and replaced by: $$g = \gcd(m, n) \quad \text{and} \quad l' = \frac{\operatorname{lcm}(m, n)}{\gcd(m, n)}$$ It is a known result that this game must terminate in a finite...
How can I prove that $0$, $324$, and $5184$ are the only fixed points of $f(n)=(E(n)O(n))^2$? Where $E$ and $O$ are even and odd digit sum of a number
I have been studying the following digit dynamical system. Let $E(n)$ denote the sum of the even digits of $n$, and let $O(n)$ denote the sum of the odd digits of $n$. Define $$ f(n)=\big(E(n)\,O(n)\big)^2. $$ I am interested in the dynamical system obtained by repeated iteration $$...
Differential of Verschiebung morphism
Let $G=\operatorname{Spec}(R)$ be a finite flat commutative group scheme over $S=\operatorname{Spec}(A)$ of characteristic $p>0$. Suppose the $p$-Lie algebra $\operatorname{Lie}(G/S)$ is locally free. I would like to know the $p$-mapping on $\operatorname{Lie}(G/S)$ coincides with differential...