All Questions
Tagged with bernoulli-numbers co.combinatorics
12 questions
101
votes
10
answers
16k
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Why do Bernoulli numbers arise everywhere?
I have seen Bernoulli numbers many times, and sometimes very surprisingly. They appear in my textbook on complex analysis, in algebraic topology, and of course, number theory. Things like the criteria ...
45
votes
16
answers
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What does the generating function $x/(1 - e^{-x})$ count?
Let $x$ be a formal (or small, since the function is analytic) variable, and consider the power series
$$ A(x) = \frac{x}{1 - e^{-x}} = \sum_{m=0}^\infty \left( -\sum_{n=1}^\infty \frac{(-x)^n}{(n+1)!}...
- 54.6k
16
votes
1
answer
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views
What is this sequence?
This is again a question that I asked at Stack Exchange, but got no answer so far, so I am trying here.
Let:
$$ a_n=\sum_{k\ge0}(k+1) {n+2\brack k+2}(n+2)^kB_k$$
$B_k$ is the Bernoulli number. ${n\...
- 505
8
votes
2
answers
386
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Coefficients of shifted Bernoulli polynomials
I stumbled across the following curious empirical properties of the
Bernoulli polynomials $B_n(x)$. Can anyone provide a reference or
proof?
Let $k\in\mathbb{Z}$, $k\geq 2$. Then (empirically):
The ...
- 50.8k
7
votes
0
answers
252
views
Hankel determinants for some convolutions of Catalan numbers
Let $c(x)=\frac{1-\sqrt{1-4x}}{2x}$ be the generating function of the Catalan numbers and let $$x^k c(x)^{2k}=(c(x)-1)^k =\sum_{n\geq0}c(k,n)x^n.$$
Consider the determinants $$D(k,n,m)= \det\left(c(k,...
- 5,622
4
votes
1
answer
260
views
Kummer's congruence at $p=3$
Let $B_{2k}$ be the Bernoulli numbers of even index and $\varphi(n)$ be Euler's totient function. We recall one instance of Kummer's congruences: for each integer $m\geq1$ and a prime number $p\geq5$, ...
- 43.2k
4
votes
0
answers
128
views
A combinatorial triangle for the Bernoulli numbers
Motivation: We informally call an infinite lower triangular matrix
$\operatorname{T}(n, k)$ of integers a combinatorial triangle of a sequence of integers or
rational numbers if it can be obtained ...
- 251
3
votes
1
answer
507
views
Conjecture on bernoulli numbers and binomial coefficients
Crossposted from
https://math.stackexchange.com/questions/4116414/conjecture-on-bernoulli-numbers-and-binomial-coefficients
In playing around with some formulas, I have come up with the following ...
- 133
3
votes
0
answers
186
views
Combinatorial interpretation of Sylvester–Lipschitz formula?
If we denote the Bernoulli numbers by $B_n$, then
$$ {a^{k+1}(a^{2k} - 1) B_{2k} \over 2k}\in \mathbb{Z}$$
for any $a\in \mathbb{Z}$ and $k\in\mathbb{N}$. This fact is often called the Sylvester–...
- 82.7k
3
votes
0
answers
157
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Combinatorial interpretation for Möbius-poly-Bernoulli numbers
The Möbius-Bernoulli numbers ,are related to Dedekind Sums
$$\sum_{d|n}\frac{t\mu(d)}{e^{td}-1}=\sum_{k=0}^\infty M_k(n)\frac{t^k}{k!}$$ where $|t|<\frac{2\pi}{n}$, and $M_k(1)=B_k$.
We define the ...
user160903
1
vote
2
answers
211
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Bilinear recurrence relation between even Bernoulli numbers
Throughout this question $n$ is a positive integer greater than 1.
Consider the following well-known identity by Euler,
$$\sum_{k=1}^{n-1} \binom{2n}{2k}B_{2k}B_{2n-2k}=-(2n+1)B_{2n}.$$
Rather ...
- 195
1
vote
1
answer
141
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Simplifying a rational function in terms of Bernoulli numbers and polynomials
Faulhaber's formula expresses a sum over some finite number of naturals to the $m^{th}$ power in terms of the Bernoulli numbers $B_{j}$ (using the $B_{1} = 1/2$ convention) or polynomials $\hat{B}_{j}$...
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