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1 vote
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Alternating sum of integer coefficients of the triangles related to Eulerian numbers and binomial transforms

Let $W(n, k, m)$ be an integer coefficients defined for $n > 0, 1 \leqslant k \leqslant n, m > 0$ with $W(n,k,m)=0$ for $n \leqslant 0$ or $k \leqslant 0$ such that $$ W(n, k, m) = (k+m-1)W(n-1,...
Notamathematician's user avatar
5 votes
3 answers
943 views

How to find the coefficient of $x^k$ in the expression $\prod_{p=1}^n (x^p+1)^p$?

I tried to find the indefinite integral $$ f_n(x)=\int \prod_{k=1}^n \cos^k(kx) \, dx$$ by using Euler's formula and put $x=\frac{\ln y}{2i}$ I got $$ f_n(x)=-i2^{-\frac{n(n+1)}{2}-1}\int y^{-\frac{n(...
Faoler's user avatar
  • 513
2 votes
1 answer
113 views

Modulo $2$ binomial transform of A243499 applied $k$ times

Let $m \geqslant 1$ be a fixed integer. Let $f(n)$ be A007814, exponent of highest power of $2$ dividing $n$, a.k.a. the binary carry sequence, the ruler sequence, or the $2$-adic valuation of $n$. ...
Notamathematician's user avatar
0 votes
1 answer
149 views

Modulo $2$ binomial transform of A124758

Let $f(n)$ be A153733, remove all trailing ones in binary representation of $n$. Here \begin{align} f(2n)& = 2n\\ f(2n+1)& = f(n)\\ \end{align} Then we have an integer sequence given by \begin{...
Notamathematician's user avatar
1 vote
0 answers
57 views

Inverse modulo $2$ binomial transform of generalised A284005

Let $m \geqslant 1$ be a fixed integer. Let $\operatorname{wt}(n)$ be A000120, $1$'s-counting sequence: number of $1$'s in binary expansion of $n$ (or the binary weight of $n$). Let $f(n)$ be A007814, ...
Notamathematician's user avatar
1 vote
0 answers
156 views

Open tours by a biased rook (proof verification)

Related questions: Number of open tours by a biased rook on a specific $f(n)\times 1$ board which end on a $k$-th cell from the right Sum with products turned into subsequences Combinatorial ...
Notamathematician's user avatar
0 votes
2 answers
400 views

Solving a recurrence relation involving binomial coefficients

This question originates from a graph neural network architecture (see 1) in which an edge-labelled graph $G=(V,E,\eta)$ of size $|V|=n$ with $\eta:E\to \mathbb{R}^{s_0}$ is represented as a "tensor''...
Sirolf's user avatar
  • 493
2 votes
1 answer
871 views

Find closed-form expression to $f(n)$

For all $n \in \mathbb{N}$, let ${\mathcal A}_n := \left\{\lceil n/2\rceil, \lceil n/2\rceil+1,\dots, n-1 \right\}$ and $$f(n) := \begin{cases} \min\limits_{a \in {\mathcal A}_n} \frac 1 4 \binom n a ...
Dudi Frid's user avatar
  • 265
2 votes
0 answers
85 views

Closed form for unusual recurrence

We have for $k>0$, $n>0$, $m\geqslant0$ $$p_k(n,m)=k(n-1)!\sum\limits_{s=0}^{n-1}\frac{p_{k-1}(s+1,m+1)+p_{k-1}(m+1,s)}{s!}$$ also $$p_0(n,m)=\begin{cases} (n-1)!,&\text{$n>0, m=0$}\\ 0,&...
user514787's user avatar
3 votes
1 answer
331 views

Solving recurrent relation

I have the following recurrent relation and I want to find a close form of it if it exists at all. $$ P_n = (1-p)^{n-1}P_{n-1} + \sum\limits_{k=2}^{n} \binom{n-1}{k-1} p^{\binom{k}{2}} (1-p)^{k(n-k)} ...
Eugene's user avatar
  • 342
1 vote
0 answers
236 views

Solving a recurrence (with the form of a convolution) involving binomial coefficients

While dealing with a problem related to intersection of hyperplanes I have come across the following recurrence to obtain the values of $K_{j}$ \begin{array}{cccccccccc} 1 & = & K_{1}\tbinom{...
josep's user avatar
  • 11