Questions related to the different ways of expressing an integer as a sum of integers; or, questions related to the subdivision of a set into smaller disjoint sets; questions related to the subdivision of an interval into smaller intervals that intersect only at the endpoints.

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Partition Generating Function (Truncation)

Let $P(x)=\sum_{n=0}^{\infty} p_nx^n$ be the partition generating function, and let $P^*(x)=\sum_{n=0}^{\infty} p^*_nx^n$, where $$p^*_n = \binom{\text{number of partitions of }n}{\text{into an even ...
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52 views

Partitioning real numbers with sum $1$ to sets

If the sum of a finite number of positive real numbers is $1$ and each of them is less than $x$, then those real numbers can be partitioned into $50$ sets (some of which may be empty) such that the ...
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129 views

Counting problem of combinations of symmetric matrix.

Given, a symmetric $n*n$ matrix $G$ with 0,1 entries. Each row of has same number of 1. $G$ is arranged in a certain order using a rule. The rule is described below- $G$ is partitioned in to two sub ...
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18 views

On t-core partitions

How exactly can one define what is known as a t-core partition? I know (vaguely) that it involves the definition of what is known as "Hook numbers". Anyone cares to provide a link or explain it?
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Terminology: Opposite of “refinement”

Let A be a partition of a set, and B a refinement of A. Fill in the blanks: A is a __________ of B. I know that A is coarser than B, but how does one turn that into a noun?
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22 views

Find largest regions bounded by a set of planes

Suppose we are given a set of planes that partition the unit cube into a large number of regions. Is there a computationally efficient way to find the region with the largest volume?
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36 views

Does Euler's recurrence relation for partitions imply that the partition function grows exponentially

Can one, just by manipulating the series, demonstrate that the partition function must be growing exponentially or at least that it is unbounded by any polynomial? If so, then how would it be done. ...
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19 views

What is wrong with this “inference” about partitions?

Given that: $p(n)=p(n-1)+p(n-2)-p(n-5)-p(n-7)+⋯$ Why can one not state: $p(n)≥p(n-1)+p(n-2)-p(n-5)-p(n-7)$ Here is the logic: the subsequent 2 terms of the relation are additive and the 2 ...
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35 views

Famous Arithmetic property of lotteries - restricted partition of integer into exactly k distinct parts between a given set

I would like to find a complete explanation regarding a famous arithmetic property of lotteries : Let´s say a friend of us is a regular player of a lottery where 5 numbers are taken from a box ...
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23 views

Determining probabilities of set of independent experiments from probability of different subsets?

I have a population C of candidates C1..Cn An event will occur to Ci with unknown probability Pi (Pi are independent) The population is divided into disjoint sets S1..Sm For each sub set Si, P(Si) is ...
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199 views

Is every integer $\geq5$ the sum of two primes and a power of a prime?

Is every integer $\geq5$ the sum of two primes and a power of a prime (where $1$ is included in the prime powers)? I don't really expect someone to prove this here, but I wonder if the question has ...
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35 views

How to partition into more than two subsets

Given a set $A$ of numbers and the number of desired subsets, $n$, how can I divide the numbers in set $A$ into $n$ subsets where each number in $A$ is used in one and only one subset and the sum of ...
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52 views

Partitioning items into fixed size sets

I have the following problem: Given $n$ items, where each item has weight $w_{i}$, $i=1,2\ldots n$, what is the number of ways to partition these items into boxes of fixed size $C$, such that the sum ...
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49 views

partitions of finite set in same-size parts having at most one element in common

Given g ≥ 2, k ≥ 1 and a population of p = kg workers, I'm trying to figure out the longest series of work shifts such that: during each shift, all workers work in k teams of g people; any two ...
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78 views

Expansion for r-associated Stirling numbers of the second kind

I am looking for a paper or guidance for expanding the r-associated Stirling numbers of the second kind $S_r(n,k)$. $S_r(n,k)$ is the number of ways to partition a set of n objects into k subsets, ...
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46 views

Expected Max Pseudotree Size

I'm working on a problem where I need to calculate the expected maximum pseudotree size in a randomly-generated pseudoforest with $n$ nodes. Expected maximum value is of course: $$ E(x) = ...
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115 views

Proving Identities using Partition and Generating Function

I have a problem with these two questions: Let $P_E(n)$ be the number of partitions of $n$ with an even number of parts, $P_O(n)$ the number of partitions of n with an odd number of parts, and ...
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26 views

Existence of finite Darboux sum with infinite partition

I would like to describe the class of all functions $a\in L^1(\mathbb{R},dx)$, such that there exists $\tilde{a}=a$ a.s. and a size $h$ of an infinite partition of $\mathbb{R}$, such that ...
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40 views

Standard form for partitions of $Z_n$

Let $A$ and $B$ be partitions of $Z_n$. Let's say that $A$ and $B$ are equivalent if $A=Bx+y$ for some $x\in{1,−1}$ and $y\in Z_n$. In other words, two partitions are equivalent if one can be obtained ...
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66 views

No simple closed form for Bell numbers

The Bell number $B_n$ is the number of partitions of $[n]$. Unlike other basic combinatorial quantities, $B_n$ has no simple finite closed form. This seems surprising to me. Can anyone explain why ...
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26 views

Proof of the formula for the number of components in all partitions of a given number

I have to show that this formula is the number of components in all partitions of number $n$: $$\sum_{i=1}^{n}\sum_{j=1}^{[n/i]}\sum_{k=0}^{n-ij}A_i(k) \cdot A_{j-1}(n-ij-k)$$ $A_k(n)$ is number of ...
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73 views

Integer partitions without rotated solutions?

I'm searching for an algorithm to determine a list of all integer partitions of a number $n$ into a fixed number $m$ of summands (say $n=6$ and $m=4$), for instance to be stored into a list of ...
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75 views

How to describe any partition a set

For ignore of a better word, I will use word "partition" try to describe what I mean. How to describe partition(where over lapping subsets are allowed) of a set mathematically? In another word, ...
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38 views

Bound and parity integer-partition into fixed number of parts

Let $E(n,k)$ denote how many set of $k$ distinct non-negative integer are there such that their sum is an even number $\leq n$. Let $O(n,k)$ denote how many set of $k$ distinct non-negative integer ...
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61 views

Generation of n terms that sums to a specific value?

I'm about to conduct an integer program where I am to transport some products from different cities to docks and refinement stations. I am however required to work with simulated data where I only ...
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138 views

Definition of a Regular Partition of a Closed Generalized Rectangle in $\mathbb R^n$

What the heck does this definition of a regular partition $P$ of $R$ mean? I follow what it is saying until we get to the last part, "the $k_1\cdot k_2\cdot \cdots \cdot k_n$ subrectangles of the ...
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22 views

Limits and integration

I have the following quick question: Consider bounded open domain $O \subset \mathbb{R}^{n}$ assume that we partition $O$ into $O_{1}^{m}$ and $O_{2}^{m}$ such that $O_{1}^{m},O_{2}^{m} \subset O$, ...
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90 views

Explanation of block systems and group action

According to Wikipedia: "If $B$ is a block then $gB$ is a block for any $g$ in $G$. If $G$ acts transitively on $X$, then the set $\{gB \mid g \in G\}$ is a block system on $X$." i.e., $\{gB \mid g ...
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74 views

Monoid on ordered partitions of a natural number

Fix a natural number $n$, and let $O_n$ be the set of ordered partitions of $n$. For example $O_3=\{1+1+1,1+2,2+1,3\}$ which can also be written as $\{1|2|3,1|23,12|3,123\}$. We can define two ...
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29 views

Finding equivalence relations containing specific equivalences

"Find the number of equivalence relations on the set $\{1,2,3,\ldots,7\}$ such that: a) $1\sim2$ and $3\sim4$. b) $1\not\sim2$, $1\not\sim3$ and $3\not\sim2$." Solving this problem is equivalent to ...
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41 views

Partitions that have at most k parts and all parts <= j

Let p¯k(n) be the number of partitions of n with largest part at most k which is equivalent to partition into at most k parts. I do know an expression for that function. ( product of 1/1(1-n) through ...
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63 views

Teminology: Partitioning a Set Including Empty Partitions

Mostly I see a partition of a set A defined as a collection of non-empty disjoint sets whose union is A. I see one reference that allows empty sets to be included in the partition: ("Potter, M. "Set ...
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50 views

Discriminating integer partitions

Given a fixed positive integer, say $n$, letn $P_n$ be the set all partitions of $n$, where each partition itself is a set i.e. order is discarded and each part is less than 5. Can we establish a ...
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69 views

Running the Greene-Nijenhuis algorithm backwards

Let $Y$ be a Young tableau of shape $\lambda:=(\lambda_1,\ldots,\lambda_n)$, where $\lambda_1\geq\lambda_2\geq\ldots\geq\lambda_n$ and $N:=|\lambda|:=\sum_i\lambda_i$. I'll be using the English ...
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59 views

Non-standard partition of integers question

The question is as follows. Partition an integer $n$ into $r$ distintc parts with each part ranges from $[1,m]$ and the parts order is irrelevant. How many ways of different partitions are there? ...
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41 views

What is the big-$\mathcal{O}$ bound for the sum of function applied to the partitions of a set?

Consider a set $A$ that is partitioned into $n$ subsets $A_1 | A_2 | ... | A_n$ and a function $f \in \mathcal{O}(g)$. Question: what is the tightest bound I can establish for $\sum_{i=1}^n ...
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139 views

Shifted Young tableaux & Hook numbers & Bulgarian Solitaire

I would like to find articles or documentation regarding this process: Starting from what ever integer partition, e.g. 5,2 for the number 7. Construct his Young tableaux and then fill it with Hook ...
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162 views

Number of solutions (excluding permutations of variables' values) and solving in distinct positive integers the following system of equations

Questions and important info in italics, very important ones in bold. Here we have the system; $V_{1}+V_{2}\cdots+V_{k}=A$ and $V_{1}^{2}+V_{2}^{2}+\cdots +V_{k}^{2}=B$ where $V_{1}$, $V_{2}$, etc. ...
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118 views

Partition of unity. Functional analysis

Need to find partition of unity in case of oparator $A_{f}(x)=(|x-1|+x)f(x)$. Operator $A \in L_{2}[0,2]$ Partition of Unity is set of operators $E_{\lambda}=E((- \infty,\lambda]) $, where ...
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136 views

Given $x = \sum_{i \in k} a_i$ from $\{ a_1, \ldots, a_n \}$, partition $x$ as $\sum_{j \in k} a_j$

Let me put this into an example. We have an array of the first $r$ (example $r=7$) natural numbers; $1, 2, 3, 4, 5, 6, 7$ and given $k=3$, so you get to select any three integers from the pool ...
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161 views

Jordan Measure, Semi-closed sets and Partitions

From earlier question here. Consider $$\mu \left( (0,1) \cap \mathbb Q \right) = 0$$ where $$(0,1) = \left(0,\frac{1}{3}\right)\cup \left[\frac{1}{3}, \frac{2}{3}\right] \cup \left(\frac{2}{3}, ...
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61 views

What is wrong with my proof by exhaustion?

$n$ colored balls are placed in an urn, with $c$ colors such that there are an equal number of balls of each color. What is the expected number of distinct colors in $k$ randomly picked balls, ...
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12 views

k-way graph partitioning with bounded size constraint

A typical $k$-way graph partitioning problem is to partition a weighted graph into $k$ components, with the constraint that all $k$ components have the same size. However, if we drop the same size ...
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Decomposition of a Set System into Distributive Lattices

I would like to decompose an arbitrary set system $S$ over a universe $U$ into a number of distributive lattices such that these lattices partition $S$. Now, I am interested in the least number of ...
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6 views

Relation between singular/eigen values of PCA partition with singular value of all the data

I'm trying to find a relationship between the singular values (or eigen values) of data with the singular value of a partition of that data obtained as follows. The data is partitioned based on the ...
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26 views

Edge-partition graph into maximum distinctive paths

Is anyone aware of a graph partitioning algorithm in which each partition is a path and where the criteria for partitioning is to maximise the difference between partitions where two paths are ...
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29 views

Number Partitioning of summands

So, I need to partition the number 133 in 1, 2 and 3. Like $$133 = 128*1 + 1*2 + 1*3$$ $$133 = 126*1 + 2*2 + 1*3$$ $$133 = 125*1 + 1*2 + 2*3$$ Where I always must use at least one 1, 2 or 3. I ...
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Indexing for partitions

I'm using spatial hashing for broad-phase collision detection and I'm trying to squeeze some more performance out of it. Currently, it creates a new hashset for every partition which works well ...
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32 views

Can you partition a rectangle into exactly 3 congruent non-rectangular parts?

Recently I came upon the following result: Theorem (*): Let $n$ be a positive integer not equal to $1,3,5,7,9$. Then it is possible to partition a rectangle into exactly $n$ congruent non-rectangular ...
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75 views

Proof of Ramanujan's Identities of Euler's Function

Consider Euler's Function defined as (and not to be confused with the totient!) $$ \phi(x) = (1-x)(1 - x^2) (1 - x^3 ) .... = \prod_{i=1}^{\infty} \left[(1 - x)^i \right] = (1;x)_{\infty}$$ ...