Skip to main content

All Questions

0 votes
0 answers
56 views

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 \...
Decaf Sux's user avatar
  • 231
1 vote
0 answers
121 views

Minimizing the magnitude of the sum of a vector of complex numbers with an integer constraint

Let $h_{1}, ..., h_{N} \in \mathbb{C} $ Consider minimizing the function below: $ \min \left| \sum\limits_{i=1}^N h_{i} x_{i} \right| $ with the constraints $x_{i}^2 = 1$ i.e., $x_{i}$ can only take ...
CES's user avatar
  • 11
3 votes
1 answer
79 views

Sum of integers closest to a given number

I have the following problem at hand: Given an odd number $n > 7$, find a set of non-negative integers $m_7$, $m_8$, ..., $m_{13}$ and $m_{14}$, such that the sum $m_7\cdot 7 + m_8\cdot 8 + ... + ...
Ubuntu_fan's user avatar
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
5 votes
2 answers
412 views

Maximizing product of three integers

It is well-known that, if we want to partition a positive number $m$ into a sum of two numbers such that their product is maximum, then the optimal partition is $m/2, ~ m/2$. If the parts must be ...
Erel Segal-Halevi's user avatar
3 votes
0 answers
52 views

How to find smallest sum of denominators so that sum of fractions is less than or equal to 1, given the numerators? [closed]

Given $n$ positive integer numbers $a_1, a_2, \dots, a_n$, how do I find $n$ positive integer numbers $b_1, b_2, \dots, b_n$, so that $$\frac{a_1}{b_1} + \frac{a_2}{b_2} + \dots + \frac{a_n}{b_n} \leq ...
sal_guy's user avatar
  • 131
1 vote
0 answers
44 views

Partition an integer $n$ into parts so as to maximize the product of the parts [duplicate]

We are given an integer $n\geq 3$. Our goal is to partition $n$ into $k$ parts $p_1, p_2, \ldots, p_k$ with $p_1 + p_2 + \ldots + p_k = n$ (for an arbitrary $k$ we can choose) so as to maximize the ...
MeyCJey's user avatar
  • 281
1 vote
1 answer
30 views

Searching for the right partitions

I have a set of integers $U$ with cardinality $311$ and whose sum is 500 dollars. I want to group all the elements of this set into three different subsets: The sum of the elements of subset $A$ is $...
Andrés González's user avatar
1 vote
0 answers
88 views

Maximum value, function of partition and its conjugate

Suppose that we have $n\in \mathbb{Z}_{+}$ and some $\alpha\ge 3$. I am trying to find maximum value of: $\sum_{i,j=1}^{n}|\lambda_{i}-\lambda_{j}^{*}|^{\alpha},$ over $\{\lambda\in \mathbb{Z}^...
user avatar
1 vote
0 answers
46 views

similar to landau's function, but all elements are odd

Everyone knows about landau's function, then I was curious about the lcm of partition "n" which element's are all odd numbers. for example: $$8=3+5 \Rightarrow f(8)=15$$ $$19=3+5+11 \Rightarrow f(...
collegues's user avatar
0 votes
0 answers
421 views

Partition a number $n$ in exactly sum of $k$ distinct numbers such that product of the numbers should be maximum.

The question is to partition a given number $n$ in exactly sum of $k$ distinct positive numbers such that the product of $k$ distinct number become maximum. $k$ will be given optimally so that it will ...
Shivam Sahu's user avatar
0 votes
0 answers
42 views

Upper bound of number of k-tuples whose components are non-negative integers and sum up to n?

Is there any nontrivial upper bound for the size of $\{(x_1,\dots,x_k)\in\mathbb{N}^k:\sum_{i=1}^kx_i=n\}?$ We may assume $k,n$ are large enough but $k\ll n$, so an asymptotic bound is also helpful.
Connor's user avatar
  • 2,085
0 votes
1 answer
79 views

discrete convexity arising in a simple discrete optimization problem

Let $S$ be a fixed integer satisfying $S \ge 1$, let $a$ range over the integers between $1$ and $S$ inclusive, and for $i = 1, \dotsc, a$, let each $x_i$ range over the nonnegative integers, such ...
A.E. Charman's user avatar
1 vote
0 answers
27 views

Use of the "Optimality Principle" in a problem regarding maximization of a product indexed by a partition of a natural number.

I am currently reading a paper (Iterated Binomial Coefficients by S.W. Golomb, The American Mathematical Monthly, 1980, 719-727) that makes use of the "optimality principle" in a couple of proofs. One ...
Oiler's user avatar
  • 3,423
0 votes
1 answer
285 views

Maximizing the sum of exponentials whose exponents sum to $N$

Let $N \geq 1$ be a sufficiently large integer, let $a > 1$ be a real number, and let $n_1, \dots, n_t$ be integers between $0$ and $K$, where $K$ divides $N$. I want to determine the following: $$...
JeremyKun's user avatar
  • 3,600

15 30 50 per page