G.Kós's user avatar
G.Kós's user avatar
G.Kós's user avatar
G.Kós
  • Member for 10 years
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20 votes
Accepted

Find the number of all subsets of $\{1, 2, \ldots,2015\}$ with $n$ elements such that the sum of the elements in the subset is divisible by 5

15 votes
Accepted

n-simplex in an intersection of n balls

11 votes
Accepted

$a^b+2$ or $a^b-2$ is in set

11 votes

Is the following limit finite ....?

10 votes

Proving positive definiteness of matrix $a_{ij}=\frac{2x_ix_j}{x_i + x_j}$

10 votes

How find the maximum value of $|bc|$

9 votes

Rings in which binomial theorem holds for at least one integer $n>2$

9 votes

When $x$ is a real number and $x>1$, why is $x^x>(x+1)^{x-1}$?

8 votes

Function analytic in each variable does not imply jointly analytic

8 votes
Accepted

Relationship between Cauchy's Integral formula and Poisson kernel

7 votes

An integral involving a smooth function

7 votes
Accepted

Let $f(z)$ be analytic in the unit disc,

7 votes
Accepted

$n^a$ integral for all integer $n$ implies $a$ integral

7 votes
Accepted

How to prove there exist distinct $a_{i}$ such $f'(a_{1})f'(a_{2})f'(a_{3})\cdots f'(a_{n})=1$

7 votes
Accepted

Conjecture about the limit of $\left(\frac1n\sum_{k=r}^n n^{\frac1k}\right)^{n^{c}}$

7 votes
Accepted

Entire function $f(z)$ grows like $\exp(x^\pi)$ as $x\to+\infty$

6 votes

A polynomial $p(x) \in \Bbb R_{2n-1}[x]$, $p(0) = 0$, $p(x) \geq 0 \ \forall x \geq 0$, can be written as $p(x) = xq_1(x)^2 + q_2(x)^2$

6 votes

Number of factors of $2^{p_1\cdots p_n}+1$

6 votes
Accepted

Prove that $2^{n(n+1)}>(n+1)^{n+1}\left(\frac{n}{1}\right)^n\left(\frac{n-1}{2}\right)^{n-1}\cdots \left(\frac{2}{n-1}\right)^{2}\frac{1}{n}$

6 votes
Accepted

Example of a Borel measure, which is not Borel-regular

6 votes

Estimate the bound of the sum of the roots of $1/x+\ln x=a$ where $a>1$

6 votes
Accepted

Inequality of absolute values of complex sums

6 votes
Accepted

Some inequalities for an entire function

6 votes
Accepted

Automorphism group of a lattice's Voronoi cell

6 votes

Does $f\Big(x+\frac{1}{n}\Big) \to f(x)$ for a.e. x as $n \to \infty$?

6 votes

A snappy proof of Fatou's lemma

5 votes
Accepted

Is there a better way to find the polynomial equation for this curve?

5 votes
Accepted

Using resultants to check if multivariate polynomials have a common factor - is my proof correct?

5 votes

Which polynomials fix the unit circle?

5 votes
Accepted

Asymptotic development of a recurrent sequence

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