Questions tagged [integer-partitions]
Use this tag for questions related to ways of writing a positive integer as a sum of positive integers.
1,433
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Find generating function for the number of partitions which are not divisible by $3$. [duplicate]
I'm trying to find the generating function for the number of partitions into parts, which are not divisible by $3,$ weighted by the sum of the parts. My idea is that we get the following generating ...
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Estimate the order of restricted number partitions
There are $k$ integers $m_l,1\leq l\leq k
$(maybe negetive), satisfiying $|m_l|\leq M$ and $\sum_l m_l=s$.
I want to get an order estimate of the number of solutions for $k, M$ when fixing $s$.
I came ...
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Computing integer partitions subject to certain constraints
Context:
I am programming a videogame.
Background:
Let $I$ be a set of named items such that each is assigned a difficulty score, and each is tagged either as "food" or "obstacle". ...
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A generalized subset sum problem
I'm looking at a problem I believe is combinatorial.
Find all possible solutions $\mathbf{x}$ to:
$$\mathbf{a} = [a_1, a_2, ..., a_n], a_k \in \mathbb{N^+}$$
$$\mathbf{l} = [l_1, l_2, ..., l_n], l_k \...
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Name of such combinatorial numbers. [duplicate]
Let $k,n\in\mathbb{N}$. Let $N(k,n)$ denote the size of the finite set
$$\{(x_1,\cdots,x_k)\in\mathbb{N}^k:x_1+2x_2+\cdots+kx_k=n\}. $$
I feel it special and important. Do $N(k,n)$ have names? Is ...
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Partial Orders on Integer Partitions
My question is the following: An integer partition $\lambda$ can be represented as an integer sequence $(f_1,f_2,f_3, \cdots)$ where $f_i$ is the number of parts used in $\lambda$. For instance, $4 + ...
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Has anyone found a closed-form expression for the strict partition function?
More precisely, if anyone has found it, could they provide links, please? I have been trying to find such a solution and have not seen one.
For context, when I try to solve the strict partition ...
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Graded ring generated by finitely many homogeneous elements of positive degree has Veronese subring finitely generated in degree one
Let $S=\bigoplus_{k\ge 0}S_n$ be a graded ring which is generated over $S_0$ by some homogeneous elements $f_1,\dotsc, f_r$ of degrees $d_1,\dotsc, d_r\ge 1$, respectively. I want to show that there ...
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Congruences of partitions and Legendre symbol.
Let $(\frac{a}{p})$ denote the Legendre symbol, and let $\psi(q)=\sum_{n\geq 0} q^{n(n+1)/2}$.
We define Ramanujan's general theta function $f(a,b)$ for $\mid ab \mid <1$ as
$$
f(a,b)=\sum_{n=-\...
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"Factorization" of the solutions set of a system of linear diophantine equations over non-negative integers
Suppose we have a system of linear diophantine equations over non-negative integers:
$$
\left\lbrace\begin{aligned}
&Ax=b\\
&x\in \mathbb{Z}^n_{\geq0}
\end{aligned}\right.
$$
where $A$ is a ...
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irregularities in partition function modulo n
It is an open problem whether the partition function is even half the time. Inspired by this, I wrote some Sage/Python code to check how many times $p(n)$ hits each residue class:
...
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Show the partition function $Q(n,k)$, the number of partitions of $n$ into $k$ distinct parts, is periodic mod m
Let $Q(n,k)$ be the number of partitions of $n$ into $k$ distinct parts.
I want to show that for any $m \geq 1$ there exists $t \geq 1$ such that
$$Q(n+t,i)=Q(n,i) \mod m \quad \forall n>0 \forall ...
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A sum of multinomial coefficients over partitions of integer
I denote a partition of an integer $n$ by $\vec i = (i_1, i_2, \ldots)$ (with $i_1, i_2, \ldots \in \mathbb N$) and define it by
$$
\sum_{p\geq1} p i_p = n.
$$
I set
$$
|\vec i| = \sum_{p\geq1} i_p.
$$...
- 1,670
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A tagged partition interval subset relations problem.
The problem was taken from “Introduction to Real Analysis” by R. Bartle and D. Sherbert, Section 7.1, Exercise 4.
Let $\dot{\mathcal{P}}$ be a tagged partition of $[0,3]$.
(a) Show that the union $U_1$...
user1055322
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Find generating series on set of descending sequences, with weight function as taking sum of sequence
Given the set of all sequences of length k with descending (not strictly, so $3,3,2,1,0$ is allowed) terms of natural numbers (including $0$), $S_k$, and the weight function $w(x)$ as taking the sum ...
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Formula for number of monotonically decreasing sequences of non-negative integers of given length and sum?
What is a formula for number of monotonically decreasing sequences of non-negative integers of given length and sum? For instance, if length k=3 and sum n=5, then these are the 5 sequences that meet ...
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Integer partitions with summands bounded in size and number
This book says it's easy, but to me, it's not. :(
As for 'at most k summands', in terms of Combinatorics, by using MSET(),
$$ MSET_{\le k}(Positive Integer) = P^{1,2,3,...k}(z) = \prod_{m=1}^{k} \frac{...
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Generating Function for Modified Multinomial Coefficients
The multinomial coefficients can be used to expand expressions of the form ${\left( {{x_1} + {x_2} + {x_3} + ...} \right)^n}$ in the basis of monomial symmetric polynomials (MSP). For example,
$$\...
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Probability that the maximum number of dice with the same face is k
Let say we have $N$ dice with 6 faces. I'm asking my self, what is the probability that the maximum number of dice with the same face is $k$?
In more precise terms, what is the size of this set?
\...
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Why do Bell Polynomial coefficients show up here?
The multinomial theorem allows us to expand expressions of the form ${\left( {{x_1} + {x_2} + {x_3} + {x_4} + ...} \right)^n}$. I am interested in the coefficients when expanding ${\left( {\sum\...
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Prove convergence of partition sequence [duplicate]
We are given a partition of a positive integer $x$. Each step, we make a new partition of $x$ by decreasing each term in the partition by 1, removing all 0 terms, and adding a new term equal to the ...
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The Asymptotic formula of the generating function related with the partition of a positive integer
This question may be duplicate with this answer_1 and here I referred to the same paper by Hardy, G. H.; Ramanujan, S. referred to by wikipedia which is referred to in answer_1.
But here I focused on ...
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corollary of the partition congruence
I was going though the paper of Ramanujan entitled Some properties of p(n), the number of partitions of n (Proceedings of the Cambridge Philosophical Society, XIX, 1919, 207 – 210). He states he found ...
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Congrunces of partitions into distinct parts
Let $P_{d}(n)$ denote the number of partitions of n into distinct parts. The generating function of $P_{d}(n)$ s given by:
$$ \sum_{n \geq 0}P_{d}(n)q^{n}= \prod_{n \geq 0} (1+q^{n}).$$
Now let $P_{2,...
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Conjecture about integer partitions
I formulated this conjecture after reading this related question.
Let $\mathcal{P}(n) = \{P_1(n), P_2(n), \ldots \}$ be the set of all integer partitions of a positive integer $n$, and $p(n)=\vert \...
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Prove that the general formula for a sequence $a_n$ is $\frac{(-1)^n}{n!}$
Here is a sequence $a_n$ where the first five $a_n$ are:
$a_1=-\frac{1}{1!}$
$a_2=-\frac{1}{2!}+\frac{1}{1!\times1!}$
$a_3=-\frac{1}{3!}+\frac{2}{2!\times1!}-\frac{1}{1!\times1!\times1!}$
$a_4=-\frac{...
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Constrained integer partition containing particular summands
Is there a way to calculate the number of constrained integer partitions containing particular summands? By constrained, I mean, the permitted summands must be below a certain limit, such as 5. Take ...
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Counting gap sizes in a subfamily of partitions
Let $\mathcal{OD}$ be the set of all odd and distinct integer partitions. This has a generating function given by
$$\sum_{\lambda\vdash\mathcal{OD}}q^{\vert\lambda\vert}=\prod_{j\geq1}(1+q^{2j-1})$$
...
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Notation for $k$-partitions of $n$ containing at least one summand equal to $s$
I am looking for whether there is any notation for the $k$-partition number of $n$ where the partitions must include some summand $s$.
An example of the kind of notation I am looking for is $P_k^s(n)$....
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What is the maximum range of a convex finite additive 2-basis of cardinality k?
Conjecture:
Given any $d \in \mathbb{Z}_{\geq 2}$ and $k=2d-2$, we have \begin{align*}
\max \{ n : (\exists &f \in \{ \mathbb{Z}_{\geq 0} \to \mathbb{Z}_{\geq 0} \})\\ &[((\forall i \in \...
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