Skip to main content

All Questions

Filter by
Sorted by
Tagged with
3 votes
1 answer
439 views

An identity for polynomials over partitions

Given an integer partition $\lambda=(\lambda_1,\dots,\lambda_{\ell(\lambda)})$ of $n$ where $\ell(\lambda)$ is the length of $\lambda$, associate its conjugate partition $\lambda'$. Denote by $\lambda'...
T. Amdeberhan's user avatar
12 votes
3 answers
892 views

Set partitions and permanents

Let $a(n)=$ Number of ordered set partitions of $[n]$ such that the smallest element of each block is odd. ...
Deyi Chen's user avatar
  • 884
8 votes
1 answer
472 views

In search of a combinatorial reasoning for a vanishing sum

Assume $s, j \in\mathbb{N}$. Define the set $$\mathcal{A}_{j,s}:=\{(n_1,n_2,\dots,n_j)\in\mathbb{Z}_{\geq0}^j\vert \, n_1+2n_2+\cdots+jn_j=j, \, n_1+n_2+\cdots+n_j=s\}.$$ Question. Is there a ...
T. Amdeberhan's user avatar