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5 votes
1 answer
310 views

Is there a statement in Presburger arithmetic about primes this simple heuristic fails for?

I came up with the following conjecture while thinking about ways to formulate some heuristics about primes: Conjecture: Given a statement $s$ in Presburger arithmetic, using an additional unary ...
Daniel Weber's user avatar
  • 3,319
5 votes
1 answer
613 views

generating $q$-Catalan numbers

An $n$-Dyck path (or a Catalan path) is a lattice path $P$, unit East and North steps, in an $n\times n$ square grid which stays (weakly) above the main diagonal. Let $\square_n$ denote all such paths....
T. Amdeberhan's user avatar
5 votes
4 answers
2k views

Good books on arithmetic functions?

As I was studying the Möbius $\mu$ function and Gram series, I got myself some pretty nice books: Ribenboim - The New Book of Prime Number Records Apostol - Introduction to Analytic Number Theory ...
Roupam Ghosh's user avatar
5 votes
2 answers
388 views

How much do these interval collections cover?

As usual any related references are appreciated. Let $p \lt q$ be distinct primes, and for all such pairs, let $m=pq$ and let $\cal{C}$ be the collection $(m-p,m)$ of open intervals. Does (the union ...
Gerhard Paseman's user avatar
5 votes
0 answers
772 views

The Grimm Machine(s): A Collatz Conjecture Rival?

Edit 2018.08.08 This answer https://mathoverflow.net/a/307881 will be updated to give recent information about S, especially a forthcoming preprint. End Edit 2018.08.08 Just as the Collatz ...
Gerhard Paseman's user avatar
5 votes
1 answer
235 views

Algebraic independence of $a^a$ and $b^b$ for algebraic irrationals $a,b$

Let $a,b$ be algebraic irrationals. Are there conjectures or unconditional results about the algebraic independence of $a^a$ and $b^b$? Probably Schanuel's conjecture is related, maybe only $\log{a},...
joro's user avatar
  • 25.4k
5 votes
0 answers
425 views

Conjectured new primality test for Mersenne numbers

How to prove that this conjecture about a new primality test for Mersenne numbers is true ? Definition: Let $M_{q}=2^{q}-1 , S_{0} = 3^{2} + 1/3^{2} , \ and: \ S_{i+1} = S_{i}^{2}-2 \pmod{M_{q}}$ ...
Tony Reix's user avatar
  • 161
5 votes
1 answer
655 views

A theorem of Stickelberger on the number of prime ideals in a decomposition

Suppose that $p$ is unramified in a number field $K$ of degree $n$. Apparently, Stickelberger proved that $\big( \frac{Disc(K)}{p}\big) = (-1)^{n - g}$, where $g$ is the number of prime ideal factors ...
Frank Thorne's user avatar
  • 7,347
5 votes
3 answers
300 views

Closed formula for $(-1)$-Baxter sequences

The number of the so-called Baxter permutations of length $n$ is computed by $$a_n=\frac1{\binom{n+1}1\binom{n+1}2}\sum_{k=0}^{n-1}\binom{n+1}k\binom{n+1}{k+1}\binom{n+1}{k+2}.$$ There has also been a ...
T. Amdeberhan's user avatar
5 votes
1 answer
455 views

Large gaps between P2s

Gaps between consecutive primes are $O(n^{\theta+\varepsilon})$ for $\theta=0.525$ and any $\varepsilon>0.$ I was wondering if a better result is known for gaps between numbers with at most two ...
Charles's user avatar
  • 9,114
5 votes
1 answer
227 views

Unicity of additive, $(-1)$-homogeneous, and shift invariant probability measures on $\mathbf N^+$

Let $\mathcal D$ be the set of all (finitely) additive probability measures $\mu^\ast: \mathcal P(\mathbf N^+) \to [0,\infty[$ such that $\mu^\ast(k \cdot X + h) = \frac{1}{k} \mu^\ast(X)$ for all $X \...
Salvo Tringali's user avatar
5 votes
2 answers
1k views

Request: Kato's article "Lectures on the approach to Iwasawa theory for Hasse-Weil L-functions." Part II

The question (similar to MO.96531) is about the article by Professor Kazuya Kato in this book. In this article, Professor Kato indicates the contents of the second part. MathSciNet does not list it, ...
SGP's user avatar
  • 3,867
5 votes
4 answers
4k views

Values of Dirichlet L-funcions at natural numbers

I want to know about reference of formulas for $$ L(s,D)=\sum_{n=1}^\infty \left(\frac{D}{n}\right)\,n^{-s} $$ for $s$ a positive integer number and $D$ a fundamental discriminant. For $s=1$ we have ...
emiliocba's user avatar
  • 2,446
4 votes
1 answer
629 views

Is $\sum_{n\leq x}{z^{\Omega(n)}} = O(x^{\frac12 + \varepsilon})$ equivalent to the Riemann hypothesis for all roots of unity $z\neq1$?

$\Omega(n)$ is the number of prime divisors of $n$, counted with multiplicity. For $z=-1$, $z^{\Omega(n)} = \lambda(n)$ is the Liouville function, and it's known that $\sum_{n\leq x}\lambda(n) = O(n^{\...
Daniel Weber's user avatar
  • 3,319
4 votes
2 answers
560 views

Asymptotics of special square-free numbers

What is the asymptotic number of square-free numbers less than $x$ with exactly $k$ prime divisors?
István Kovács's user avatar
4 votes
2 answers
288 views

Best known bounds for $\left|\sum_{n<x}\mu(nk)\right|$ (Reference request)

What is the best known bound for the Mertens function along arithmetic progressions? More specifically, what is the best bound known for $$\sum_{n<x}\mu(kn)$$ as $k,x\to\infty$. This paper of ...
Milo Moses's user avatar
  • 2,902
4 votes
1 answer
165 views

De Bruijn's sequence is odd iff $n=2^m−1$: Part II

Assume $a\in\mathbb{N}$. Among the families of sequences studied by Nicolaas de Bruijn (Asymptotic Methods in Analysis, 1958), let's focus on the (modified) $$\hat{S}(2a,n)=\frac1{n+1}\sum_{k=0}^{2n}(-...
T. Amdeberhan's user avatar
4 votes
2 answers
1k views

Fricke groups and Fricke curves

The congruence subgroup $\Gamma_{0}(n) \subset PSL_{2}(\mathbb{Z})$ is normalized by the Fricke involution $F_n: z \mapsto -1/nz$ and so we may form the Fricke modular group $\Gamma_{0}^{+}(n)\langle \...
Chris Brav's user avatar
  • 1,859
4 votes
0 answers
846 views

Reference request for a basic result on relative differents & discriminants

I am looking for a better reference for the results in this extremely short and elementary paper: Tôyama, Hiraku, `A note on the different of the composed field', Kōdai Math. Sem. Rep. 7 (1955), 43–44....
Bobby Grizzard's user avatar
4 votes
0 answers
313 views

Four-distance problem

A Problem due to Steinhaus is the following: do there exists a point in the plane at rational distance from the corners of the unit square? Please give me a reference if this problem is solved.
MasleniZZa's user avatar
4 votes
1 answer
599 views

Reference request, zeta function is rational function via Riemann-Roch?

I am looking for a reference to a proof that the zeta function of a function field in one variable over a finite field $\mathbb{F}_q$ is a rational function in $q^{-s}$ by using the Riemann-Roch ...
user74301's user avatar
4 votes
1 answer
335 views

If $N = {q^k}{n^2}$ is an odd perfect number given in Eulerian form, is $n$ a square?

(I have asked a similar question in MSE four days ago, but did not receive any answers. I have therefore cross-posted it to this site, hoping to get some responses.) An odd perfect number $N$ is ...
Jose Arnaldo Bebita's user avatar
4 votes
1 answer
523 views

Siegel-Walfisz Theorem with smooth weights

Let $$\psi(x;q,a)=\sum_{n\leq x\atop n\equiv a\pmod q}\Lambda(n)$$ where $\Lambda$ denotes the von Mangoldt function and $\phi$ to be Euler's totient function. Then the Siegel-Wafisz theorem states ...
Johnny T.'s user avatar
  • 3,625
4 votes
2 answers
470 views

On the natural density of almost perfect numbers

This question is pretty basic, so I apologize in advance if it is unsuitable for MO. If so, please do let me know and I will migrate it over to MSE. Essentially, by work of Kanold, we know that the ...
Jose Arnaldo Bebita's user avatar
4 votes
0 answers
332 views

Diophantine equations over cyclotomic fields

Let $\mathbb{Q}^{\text{ab}}$ be the compositum of all finite abelian extensions of $\mathbb{Q}$. Explicitly, $\mathbb{Q}^{\text{ab}}$ is the field obtained from $\mathbb{Q}$ by adjoining all roots of ...
Pablo's user avatar
  • 11.3k
4 votes
0 answers
409 views

An unpublished note by Spencer Bloch and Kazuya Kato

I am looking for an unpublished note by Spencer Bloch and Kazuya Kato, p-divisible groups and Dieudonné crystals. This note is always cited as Spencer Bloch and Kazuya Kato, p-divisible groups and ...
Mayday's user avatar
  • 193
4 votes
1 answer
545 views

class number of biquadratic fields

Can any one provide some references which treat the relation between the class number of a biquadratic field and the class numbers of its sub-fields using the analytic class number formula ?
Zakariae.B's user avatar
3 votes
2 answers
876 views

Asymptotics for the number of partitions of $n$ into odd prime parts

Hello! I am interested in the asymptotic behavior of the function $p_o(n)$ defined as the number of partitions of $n$ into odd prime parts A099773 - http://oeis.org/A099773 . I couldn't find any ...
Jernej's user avatar
  • 3,463
3 votes
1 answer
562 views

Volume of PGL(2,F) \ PGL(2, A)

Let $F$ be a global field. What is the measure of $PGL_2(F) \backslash PGL_2(\mathbb{A})$? This depends of course on the normalizations of the Haar measures on $PGL_2(F)$ and $PGL_2(\mathbb{A})$. ...
Marc Palm's user avatar
  • 11.2k
3 votes
1 answer
251 views

Congruence modulo 2 for q-series

This quest arose from certain calculations with integer partitions (having distinct parts) and the corresponding values of their Dyson ranks. I would like to ask: QUESTION. Is this congruence true ...
T. Amdeberhan's user avatar
3 votes
4 answers
654 views

A generalization of Landau's function

For a given $n > 0$ Landau's function is defined as $$g(n) := \max\{ \operatorname{lcm}(n_1, \ldots, n_k) \mid n = n_1 + \ldots + n_k \mbox{ for some $k$}\},$$ the least common multiple of all ...
StefanH's user avatar
  • 798
3 votes
1 answer
480 views

Reference for explicit formula for $\sum_n \Lambda(n) \chi(n)$ with smooth weights

Let $\Lambda$ be the von Mangoldt function and $\chi$ a primitive character mod $q$, then we have the explicit formula $$ \sum_{n \leq X} \Lambda(n) \chi(n) = \delta_{\chi} X - \sum_{ |Im \ \rho| \leq ...
Johnny T.'s user avatar
  • 3,625
3 votes
2 answers
505 views

On odd perfect numbers and a GCD

(Note: This question is closely related to this other one in MSE.) Let $N = q^k n^2$ be an odd perfect number. From this paper in NNTDM, we have the equation $$i(q) := \frac{\sigma(n^2)}{q^k}=\frac{...
Jose Arnaldo Bebita Dris's user avatar
3 votes
1 answer
447 views

A number array related to colored necklaces and the primes

I stumbled upon entry OEIS-A208535 on the enumeration of certain kinds of colored necklaces and noticed that the integers for the odd prime rows of the table there seem to be given by the Moreau ...
Tom Copeland's user avatar
  • 10.5k
3 votes
1 answer
528 views

Karolyi's theorem for finite groups and its extensions

Suppose that $\mathbb A = (A, +)$ is a (possibly non-commutative) group, and denote by $p(\mathbb A)$ the minimum of $|S|$ as $S$ ranges in the set of non-trivial subgroups of $\mathbb A$, with the ...
Salvo Tringali's user avatar
2 votes
2 answers
345 views

Looking for a reference to a classical formula for the sum of the base-$b$ digits of an integer

Pick an integer $b \ge 2$, and for $n \in \mathbf N$ let $s_b(n)$ denote the sum of the base-$b$ digits of $n$. It is a nice exercise to prove that $$s_b(n) = (b-1) \sum_{i=1}^\infty \left\{\frac{n}{b^...
Salvo Tringali's user avatar
2 votes
1 answer
1k views

Sum of the digits in base $p+1$

Definition Let $W$ be the function , defined as $W(a,b)=r$ given $a,b\in \mathbb{Z_+}$ and $a>1$ Take $m$ to be the integer s.t. $a^{m+1} \ge b > a^{m}$, i.e. $m = \...
Pruthviraj's user avatar
2 votes
3 answers
515 views

Asymptotic number of zeros for Dirichlet series with functional equation

I think the usual proof for the asymptotic number of zeros of the Riemann zeta function $$N(T) = \#\left\{\rho : \ \zeta(\rho)=0, \begin{array}{l}\scriptstyle Im(\rho)\ \in\ [0,T]\\ \scriptstyle Re(\...
reuns's user avatar
  • 3,403
2 votes
5 answers
611 views

A good introduction to the study of the Thue Equation

Hi, I am interested in studying the Thue equation, where we are concerned with a binary form $F(x,y) = a_0 x^r + a_1 x^{r-1}y + \cdots + a_r y^r$ and solutions of the form $$F(x,y) = h$$ for some ...
Stanley Yao Xiao's user avatar
2 votes
3 answers
912 views

Reference on generators of subgroups of symplectic groups

We should start with the definition of the symplectic group for an arbitrary ring $R$. The symplectic group $Sp(g,R)$ is the subgroup of $SL(2g,R)$ such that all elements satisfy $M=J_g^t M J_g$ with $...
Tom's user avatar
  • 85
2 votes
0 answers
398 views

Counting factors: is this approach in the literature on multiperfect numbers?

Does the following approach (or something near it) exist in the number theory literature? I will provide some motivation for $\omega(p^n - 1)$ as $n \rightarrow \infty$ and for this question. First, ...
The Masked Avenger's user avatar
2 votes
1 answer
322 views

Reference request: Research done on whether the Euler prime can be the largest factor of an odd perfect number

(Note: This was cross-posted from MSE.) I posted the following reference request in MSE three (3) days ago, but was unable to elicit any responses. I am cross-posting it to MO, hoping that it is ...
Jose Arnaldo Bebita's user avatar
2 votes
1 answer
596 views

On the upper Banach density of the set of positive integers whose base-$b$ representation misses at least one prescribed digit

Let $b$ be a fixed integer $\ge 2$ and $A$ a proper subset of $\{0, \ldots, b-1\}$. Then define $X$ to be the set of all positive integers whose base-$b$ representation consists only of digits from $A$...
Salvo Tringali's user avatar
2 votes
1 answer
91 views

Reference or a short argument that a certain subset generates the ring of p-typical symmetric functions under plethysm

Let p be a prime, and let $\Lambda_p$ be the subring of the ring of symmetric functions $\Lambda$ (over $\mathbb{Z}$) such that $$x \in \Lambda_p$$ iff there is an $i \in \mathbb{N}$ such that $p^ix \...
Tedar's user avatar
  • 101
2 votes
2 answers
1k views

Place stabilizers for the absolute Galois Group

Fix an algebraic closure, $\overline{\mathbb{Q}}$ for the rationals and consider the set, $B_p$, of all places of $\overline{\mathbb{Q}}$ over a fixed (possibly infinite) prime, $p$, of $\mathbb{Q}$. ...
Adam Hughes's user avatar
  • 1,049
1 vote
1 answer
142 views

Algorithm for computing isogeny class of elliptic curve

Is there an algorithm for computing the entire isogeny class of a given elliptic curve $E/\mathbb{Q}$? References/ideas are welcome. Thanks!
kindasorta's user avatar
  • 2,907
1 vote
1 answer
344 views

Products involving exponents of tribonacci numbers

The Fibonacci numbers $F_n$ can be given by $$\sum_{k\geq0}F_kx^k=\frac{x}{1-x-x^2}.$$ Among many many properties of this sequence, consider the following two results: (1) the coefficients of the ...
T. Amdeberhan's user avatar
1 vote
1 answer
204 views

Iterated exponential sums

Does anyone have any references for iterated exponential sums? That is, sums like $$\sum_{1\leq n\leq X} e(f(n))\sum_{1\leq m\leq n} e(f(m)),$$ where $e(x)=e^{2\pi i x}$? I am looking for references ...
user479223's user avatar
  • 1,904
1 vote
1 answer
222 views

Sum over three squares

Let $x$ be a sufficiently large number. Is there an explicit or asymptotic formula for the following sum $$\sum_{\substack{n\leq x\\ n=a^2+b^2+c^2}} 1.$$ Any reference would be helpful.
Khadija Mbarki's user avatar
1 vote
1 answer
291 views

Show that, If $a-1\mid S(a-1,2m)$ and $a-1>2m+1$ then $(f(a,2m))_a\in X_a$

Define $X_a$ be the set as, namely$\{ x=(\ \underbrace{ 1\ 1\cdots\ 1\ 1}_{\text{$n$ terms}}\ \ 0 \ \ \underbrace{ \alpha_t\ \alpha_{t-1} \cdots \alpha_1 \ \alpha_0}_{\text{$k$ terms, k=t+1}})_a \mid\ ...
Pruthviraj's user avatar