arXiv subjects

Bernd C. Kellner

Publications and source records attributed to Bernd C. Kellner.

At least 19 recordsLinked to original sources

arXiv2025

Wilson's theorem modulo higher prime powers II: Bernoulli numbers and polynomials

By recent work of the author, Wilson's theorem as well as the Wilson quotient can be described by supercongruences of power sums of Fermat quotients modulo every higher prime power. We translate these congruences into congruences of power sums and Bernoulli numbers. This together provides relatively short proofs of the congruences compared to former approaches. As an application, we compute, e.g., the Wilson quotient up to modulo $p^4$ and equivalently the factorial $(p-1)!$ up to modulo $p^5$, which can be extended to any higher prime power with some effort. As a by-product, we determine some power sums of the Fermat quotients up to modulo $p^4$.

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arXiv2025

Wilson's theorem modulo higher prime powers III: The cases modulo $p^6$ and $p^7$

Extending previous work of the author, we compute the Wilson quotient modulo $p^5$ and $p^6$, and equivalently $(p-1)!$ modulo $p^6$ and $p^7$, respectively. Further, we determine some power sums of the Fermat quotients up to modulo $p^6$. Subsequently, we discuss some patterns that occur in the $p$-adic coefficients of the Wilson quotient as well as of $(p-1)!$, whereby the original congruence $(p-1)! \equiv -1 \pmod{p}$ fits perfectly into the theory.

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arXiv2025

Wilson's theorem modulo higher prime powers I: Fermat and Wilson quotients

We show that Wilson's theorem as well as the Wilson quotient can be described by supercongruences modulo any higher prime power involving terms of power sums of Fermat quotients. The new approach uses Bell polynomials and Newton's identities relating elementary symmetric polynomials to power sums. This enables us to compute certain multivariate polynomials recursively that are needed to establish the supercongruences. Subsequently, we give a recurrence formula for these polynomials and show further properties.

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arXiv2024

Asymptotic products of binomial and multinomial coefficients revisited

In this note, we consider asymptotic products of binomial and multinomial coefficients and determine their asymptotic constants and formulas. Among them, special cases are the central binomial coefficients, the related Catalan numbers, and binomial coefficients in a row of Pascal's triangle. For the latter case, we show that it can also be derived from a limiting case of products of binomial coefficients over the rows. The asymptotic constants are expressed by known constants, for example, the Glaisher-Kinkelin constant. In addition, the constants lie in certain intervals that we determine precisely. Subsequently, we revisit a related result of Hirschhorn and clarify the given numerical constant by showing the exact expression.

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arXiv2024

On the finiteness of Bernoulli polynomials whose derivative has only integral coefficients

It is well known that the Bernoulli polynomials $\mathbf{B}_n(x)$ have nonintegral coefficients for $n \geq 1$. However, ten cases are known so far in which the derivative $\mathbf{B}'_n(x)$ has only integral coefficients. One may assume that the number of those derivatives is finite. We can link this conjecture to a recent conjecture about the properties of a product of primes satisfying certain $p$-adic conditions. Using a related result of Bordellès, Luca, Moree, and Shparlinski, we then show that the number of those derivatives is indeed finite. Furthermore, we derive other characterizations of the primary conjecture. Subsequently, we extend the results to higher derivatives of the Bernoulli polynomials. This provides a product formula for these denominators, and we show similar finiteness results.

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arXiv2023

Faulhaber polynomials and reciprocal Bernoulli polynomials

About four centuries ago, Johann Faulhaber developed formulas for the power sum $1^n + 2^n + \cdots + m^n$ in terms of $m(m+1)/2$. The resulting polynomials are called the Faulhaber polynomials. We first give a short survey of Faulhaber's work and discuss the results of Jacobi (1834) and the less known ones of Schröder (1867), which already imply some results published afterwards. We then show, for suitable odd integers $n$, the following properties of the Faulhaber polynomials $F_n$. The recurrences between $F_n$, $F_{n-1}$, and $F_{n-2}$ can be described by a certain differential operator. Furthermore, we derive a recurrence formula for the coefficients of $F_n$ that is the complement of a formula of Gessel and Viennot (1989). As a main result, we show that these coefficients can be expressed and computed in different ways by derivatives of generalized reciprocal Bernoulli polynomials, whose values can also be interpreted as central coefficients. This new approach finally leads to a simplified representation of the Faulhaber polynomials. As an application, we obtain some recurrences of the Bernoulli numbers, which are induced by symmetry properties.

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arXiv2023

On the nonintegrality of certain generalized binomial sums

We consider certain generalized binomial sums $\mathcal{S}_{(r,n)}(\ell)$ and discuss the nonintegrality of their values for integral parameters $n,r \geq 1$ and $\ell \in \mathbb{Z}$ in several cases using $p$-adic methods. In particular, we show some properties of the denominator of $\mathcal{S}_{(r,n)}(\ell)$. Viewed as polynomials, the sequence $(\mathcal{S}_{(r,n)}(x))_{n \geq 0}$ forms an Appell sequence. The special case $\mathcal{S}_{(r,n)}(2)$ reduces to the sum $\sum_{k=0}^{n} \binom{n}{k} \frac{r}{r+k}$, which has recently received some attention from several authors regarding the conjectured nonintegrality of its values. So far, only a few cases have been proved. The generalized results imply, among other things, for even $|\ell| \geq 2$ that $\mathcal{S}_{(r,n)}(\ell) \notin \mathbb{Z}$ when $\binom{r+n}{r}$ is even, e.g., $r$ and $n$ are odd. Although there exist exceptions where $\mathcal{S}_{(r,n)}(\ell) \in \mathbb{Z}$, ``almost all'' values of $\mathcal{S}_{(r,n)}(\ell)$ for $n,r \geq 1$ are nonintegral for any fixed $|\ell| \geq 2$. Subsequently, we also derive explicit inequalities between the parameters for which $\mathcal{S}_{(r,n)}(\ell) \notin \mathbb{Z}$. Especially, this is shown for certain small values of $\ell$ for $r \geq n$ and $n > r \geq \frac{1}{5} n$. As a supplement, we finally discuss exceptional cases where $\mathcal{S}_{(r,n)}(\ell) \in \mathbb{Z}$.

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arXiv2022

On primary Carmichael numbers

The primary Carmichael numbers were recently introduced as a special subset of the Carmichael numbers. A primary Carmichael number $m$ has the unique property that $s_p(m) = p$ holds for each prime factor $p$, where $s_p(m)$ is the sum of the base-$p$ digits of $m$. The first such number is Ramanujan's famous taxicab number $1729$. Due to Chernick, all Carmichael numbers with three factors can be constructed by certain squarefree polynomials $U_3(t) \in \mathbb{Z}[t]$, the simplest one being $U_3(t) = (6t+1)(12t+1)(18t+1)$. We show that the values of any $U_3(t)$ obey a special decomposition for all $t \geq 2$ and besides certain exceptions also in the case $t=1$. These cases further imply that if all three factors of $U_3(t)$ are simultaneously odd primes, then $U_3(t)$ is not only a Carmichael number, but also a primary Carmichael number. Together with the exceptional cases, all Carmichael numbers with three factors have at least the property that $s_p(m) = p$ holds for the greatest prime factor $p$ of $m$. Subsequently, we show some connections to taxicab and polygonal numbers, involving the number $1729$ as an example again.

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arXiv2022

Shifted sums of the Bernoulli numbers, reciprocity, and denominators

We consider the numbers $\mathcal{B}_{r,s} = (\mathbf{B}+1)^r \mathbf{B}^s$ (in umbral notation $\mathbf{B}^n = \mathbf{B}_n$ with the Bernoulli numbers) that have a well-known reciprocity relation, which is frequently found in the literature and goes back to the 19th century. In a recent paper, self-reciprocal Bernoulli polynomials, whose coefficients are related to these numbers, appeared in the context of power sums and the so-called Faulhaber polynomials. The numbers $\mathcal{B}_{r,s}$ can be recursively expressed by iterated sums and differences, so it is not obvious that these numbers do not vanish in general. As a main result among other properties, we show the non-vanishing of these numbers, apart from exceptional cases. We further derive an explicit product formula for their denominators, which follows from a von Staudt--Clausen type relation.

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arXiv2021

On (self-) reciprocal Appell polynomials: Symmetry and Faulhaber-type polynomials

The main purpose of this paper is to study generalized (self-) reciprocal Appell polynomials, which play a certain role in connection with Faulhaber-type polynomials. More precisely, we show for any Appell sequence when satisfying a reflection relation that the Appell polynomials can be described by Faulhaber-type polynomials, which arise from a quadratic variable substitution. Furthermore, the coefficients of the latter polynomials are given by values of derivatives of generalized reciprocal Appell polynomials. Subsequently, we show some applications to the Bernoulli and Euler polynomials. In the context of power sums the results transfer to the classical Faulhaber polynomials.

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arXiv2021

On Carmichael and polygonal numbers, Bernoulli polynomials, and sums of base-$p$ digits

We give a new characterization of the set $\mathcal{C}$ of Carmichael numbers in the context of $p$-adic theory, independently of the classical results of Korselt and Carmichael. The characterization originates from a surprising link to the denominators of the Bernoulli polynomials via the sum-of-base-$p$-digits function. More precisely, we show that such a denominator obeys a triple-product identity, where one factor is connected with a $p$-adically defined subset $\mathcal{S}$ of the squarefree integers that contains $\mathcal{C}$. This leads to the definition of a new subset $\mathcal{C}'$ of $\mathcal{C}$, called the "primary Carmichael numbers". Subsequently, we establish that every Carmichael number equals an explicitly determined polygonal number. Finally, the set $\mathcal{S}$ is covered by modular subsets $\mathcal{S}_d$ ($d \geq 1$) that are related to the Knödel numbers, where $\mathcal{C} = \mathcal{S}_1$ is a special case.

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arXiv2018

The denominators of power sums of arithmetic progressions

In a recent paper the authors studied the denominators of polynomials that represent power sums by Bernoulli's formula. Here we extend our results to power sums of arithmetic progressions. In particular, we obtain a simple explicit criterion for integrality of the coefficients of these polynomials. As applications, we obtain new results on the sequence of denominators of the Bernoulli polynomials. A consequence is that certain quotients of successive denominators are infinitely often integers, which we characterize.

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arXiv2017

Distribution modulo one and denominators of the Bernoulli polynomials

Let $\{\cdot\}$ denote the fractional part and $n \geq 1$ be a fixed integer. In this short note, we show for any prime $p$ the one-to-one correspondence $$\sum_{ν\geq 1} \left\{\frac{n}{p^ν}\right\} > 1 \quad \iff \quad p \mid \mathrm{denom}( B_n(x) - B_n ),$$ where $B_n(x) - B_n$ is the $n$th Bernoulli polynomial without constant term and $\mathrm{denom}(\cdot)$ is its denominator, which is squarefree.

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arXiv2017

On a product of certain primes

We study the properties of the product, which runs over the primes, $$\mathfrak{p}_n = \prod_{s_p(n) \, \geq \, p} p \quad (n \geq 1),$$ where $s_p(n)$ denotes the sum of the base-$p$ digits of $n$. One important property is the fact that $\mathfrak{p}_n$ equals the denominator of the Bernoulli polynomial $B_n(x) - B_n$, where we provide a short $p$-adic proof. Moreover, we consider the decomposition $\mathfrak{p}_n = \mathfrak{p}_n^- \cdot \mathfrak{p}_n^+$, where $\mathfrak{p}_n^+$ contains only those primes $p > \sqrt{n}$. Let $ω( \cdot )$ denote the number of prime divisors. We show that $ω( \mathfrak{p}_n^+ ) < \sqrt{n}$, while we raise the explicit conjecture that $$ω( \mathfrak{p}_n^+ ) \, \sim \, κ\, \frac{\sqrt{n}}{\log n} \quad \text{as $n \to \infty$}$$ with a certain constant $κ> 1$, supported by several computations.

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arXiv2017

Power-Sum Denominators

The power sum $1^n + 2^n + \cdots + x^n$ has been of interest to mathematicians since classical times. Johann Faulhaber, Jacob Bernoulli, and others who followed expressed power sums as polynomials in $x$ of degree $n+1$ with rational coefficients. Here we consider the denominators of these polynomials, and prove some of their properties. A remarkable one is that such a denominator equals $n+1$ times the squarefree product of certain primes $p$ obeying the condition that the sum of the base-$p$ digits of $n+1$ is at least $p$. As an application, we derive a squarefree product formula for the denominators of the Bernoulli polynomials.

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arXiv2015

The topology of Stein fillable manifolds in high dimensions II

We continue our study of contact structures on manifolds of dimension at least five using complex surgery theory. We show that in each dimension 2q+1 > 3 there are 'maximal' almost contact manifolds to which there is a Stein cobordism from any other (2q+1)-dimensional contact manifold. We show that the product M x S^2 admits a weakly fillable contact structure provided M admits a weak symplectic filling. We also study the connection between Stein fillability and connected sums: we give examples of almost contact manifolds for which the connected sum is Stein fillable, while the components are not. Concerning obstructions to Stein fillings, we show that the (8k-1)-dimensional sphere has an almost contact structure which is not Stein fillable once k > 1. As a consequence we deduce that any highly connected almost contact (8k-1)-manifold (with k > 1) admits an almost contact structure which is not Stein fillable. The proofs rely on a new number-theoretic result about Bernoulli numbers.

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arXiv2014

Sparse matrices describing iterations of integer-valued functions

We consider iterations of integer-valued functions $ϕ$, which have no fixed points in the domain of positive integers. We define a local function $ϕ_n$, which is a sub-function of $ϕ$ being restricted to the subdomain $\{0, ..., n \}$. The iterations of $ϕ_n$ can be described by a certain $n \times n$ sparse matrix $M_n$ and its powers. The determinant of the related $n \times n$ matrix $\hat{M}_n = I - M_n$, where $I$ is the identity matrix, acts as an indicator, whether the iterations of the local function $ϕ_n$ enter a cycle or not. If $ϕ_n$ has no cycle, then $\det \hat{M}_n = 1$ and the structure of the inverse $\hat{M}_n^{-1}$ can be characterized. Subsequently, we give applications to compute the inverse $\hat{M}_n^{-1}$ for some special functions. At the end, we discuss the results in connection with the $3x+1$ and related problems.

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arXiv2014

On quotients of Riemann zeta values at odd and even integer arguments

We show for even positive integers $n$ that the quotient of the Riemann zeta values $ζ(n+1)$ and $ζ(n)$ satisfies the equation $$\frac{ζ(n+1)}{ζ(n)} = (1-\frac{1}{n}) (1-\frac{1}{2^{n+1}-1}) \frac{\mathcal{L}^\star(\mathfrak{p}_n)}{\mathfrak{p}_n'(0)},$$ where $\mathfrak{p}_n \in \mathbb{Z}[x]$ is a certain monic polynomial of degree $n$ and $\mathcal{L}^\star: \mathbb{C}[x] \to \mathbb{C}$ is a linear functional, which is connected with a special Dirichlet series. There exists the decomposition $\mathfrak{p}_n(x) = x(x+1) \mathfrak{q}_n(x)$. If $n = p+1$ where $p$ is an odd prime, then $\mathfrak{q}_n$ is an Eisenstein polynomial and therefore irreducible over $\mathbb{Z}[x]$.

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