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1 vote
1 answer
101 views

On $(0,1)$-strings and counting

Consider a binary string of length $n$ that starts with a $1$ and ends in a $0$. Clearly there are $2^{n-2}$ such bit strings. I would like to condition these sequences by insisting that the number of ...
T. Amdeberhan's user avatar
1 vote
1 answer
62 views

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". ...
A. B. Marnie's user avatar
  • 1,312
1 vote
1 answer
44 views

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 ...
Lorenzo Andreaus's user avatar
0 votes
1 answer
44 views

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 ...
An5Drama's user avatar
  • 416
19 votes
1 answer
1k views

Can we partition the reciprocals of $\mathbb{N}$ so that each sum equals 1

Let $S = \{1, 1/2,1/3,\dots\}$ Can we find a partition $P$ of $S$ so that each part sums to 1, e.g. $$P_1 = {1}$$ $$P_2 = { 1/2,1/5,1/7,1/10,1/14,1/70}$$ $$P_3 = {1/3,1/4,1/6,1/9,1/12,1/18}$$ $$P_4 = \...
AndroidBeginner's user avatar
6 votes
1 answer
83 views

Partition of a number $n$ whose each part is coprime with this number

I'm trying to solve the following problem: given an integer $n$, under which conditions of $n$ the following statement is true: For any $1 < k \leq n$, there is always a partition of $k$ parts of $...
Ta Thanh Dinh's user avatar
0 votes
0 answers
73 views

Factoring an integer $N$ using its random partition of length $3$

While working on this MSE question that I had posted, I wondered what would be a minimal base of numbers that we could work with the algorithm described in that question. I conjectured that a ...
vvg's user avatar
  • 3,341
3 votes
0 answers
50 views

$\sum_{n=1}^m \frac{1}{n!} \sum_{\sum_{i=1}^n m_i = m, \\ m_i \in \mathbb N_+} \frac{1}{m_1\cdots m_n} = 1$? [duplicate]

I found an equation accidentally when doing my research about branching processes. I think it is correct but I don't know how to prove it: \begin{equation} \sum_{n=1}^m \frac{1}{n!} \sum_{\sum_{i=1}^n ...
Dreamer's user avatar
  • 1,972
0 votes
0 answers
60 views

Books for developing an intuitive understanding of the partitions of numbers

I understand from the fundamental theorem of arithmetic that every number can be written as a product of its prime factors,but I’m curious about partitions,how numbers can be broken up into sums and ...
Wallace Monibidor's user avatar
0 votes
1 answer
33 views

Can I always split a friendly partition into two subpartitions, one of which is composed solely of 1, 2, 3, 4, and the largest part?

Suppose I have a partition $p$ of a positive integer $n$, $p$ is defined to be a friendly partition if and only if the following hold: $n$ is divisible by $4$. The length of $p$ is $\frac{n}{2}$. ...
Greg Nisbet's user avatar
  • 11.8k
1 vote
1 answer
161 views

How to make this proof rigorous by introducing partition of numbers?

Question: Let $n$ be a positive integer and $ H_n=\{A=(a_{ij})_{n×n}\in M_n(K) : a_{ij}=a_{rs} \text{ whenever } i +j=r+s\}$. Then what is $\dim H_n$? Proof: For $n=2$ $H_2=\begin{pmatrix} a_{11}&...
Ussesjskskns's user avatar
-3 votes
4 answers
129 views

Find a minimal set whose elements determine explicitly all integer solutions to $x + y + z = 2n$

Is there a way to exactly parameterise all the solutions to the equation $x + y + z = 2n$, for $z$ less than or equal to $y$, less than or equal to $x$, for positive integers $x,y,z$? For example, for ...
Noam's user avatar
  • 67
2 votes
0 answers
214 views

Maximize sum of ceiling functions

I need to find the maximum of a sum of ceiling functions. The following are given $$N,C\in\mathbb{Z}\text{ with }0\leq N\text{ and }1\leq C$$ $$\frac{p}{q}\in\mathbb{Q}\text{ with }p,q \text{ coprime ...
xdaimon's user avatar
  • 87
0 votes
0 answers
41 views

Partitions of integers with finite uses in combinatorics

I've done some research into partitions and am yet to find any resources to understand the following: Given a number $n$ and the restrictions that: Using only the numbers $1, 2, ..., m$; A maximum of ...
maxy's user avatar
  • 25
1 vote
0 answers
62 views

Number of solutions to linear equation $x_1+x_2+\dots+x_n=m$ when the domain of $x_i\ne$ domain of $x_j$

In the lecture notes of one of my previous classes, it was used that if we have an equation of the form $$\tag{1} x_1+x_2+\dots+x_n=m $$ then the total number of solutions, when each $x_i$ is a non-...
Hydrogen's user avatar
  • 175

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