User Alexey Ustinov

53 votes

34 answers

14k views

Most intriguing mathematical epigraphs

asked Sep 29, 2015 at 8:36

39 votes

3 answers

2k views

Is there a regular pentagon with a rational point on each edge?

asked Nov 25, 2023 at 7:28

35 votes

1 answer

3k views

"The Two Sheriffs" puzzle

asked Apr 17, 2015 at 12:13

35 votes

3 answers

4k views

Solve in positive integers: $n!=m(m+1)$

asked Sep 18, 2010 at 10:27

33 votes

21 answers

11k views

Applications of finite continued fractions

asked Dec 19, 2010 at 9:56

25 votes

1 answer

2k views

The origin of Discrete `Liouville's theorem'

asked Nov 22, 2013 at 11:18

24 votes

1 answer

5k views

"Gauss trick" vs Karatsuba multiplication

asked Dec 27, 2018 at 3:10

18 votes

8 answers

3k views

Open problems in continued fractions theory

asked Apr 4, 2015 at 11:01

15 votes

1 answer

773 views

$\mathbb{R}^3$ as the union of disjoint circles

asked Apr 1, 2021 at 1:33

13 votes

1 answer

897 views

Limiting shape for Brillouin zones

asked Oct 23, 2015 at 13:52

12 votes

2 answers

617 views

“The Two Sheriffs” puzzle -2: threshold for security

asked Apr 19, 2015 at 10:16

12 votes

3 answers

2k views

What is the value of $p$-adic $\zeta$-function at positive integer point?

asked Oct 21, 2015 at 7:31

12 votes

1 answer

399 views

Lengths of continued fractions for the numbers with fixed ratio

asked Oct 9, 2010 at 2:15

11 votes

1 answer

684 views

2-adic Logarithm and Resistance of n-dimensional Cube

asked Oct 29, 2013 at 13:34

11 votes

2 answers

1k views

Yang–Baxter explanation

asked Apr 3, 2015 at 13:54

11 votes

1 answer

411 views

Is Somos-8 $\mod 2$ periodic?

asked Jun 9, 2017 at 6:38

9 votes

0 answers

242 views

De Bruijn sequence inside De Bruijn sequence

asked Sep 29, 2015 at 4:17

7 votes

1 answer

268 views

On one class of Somos-like sequences

asked Apr 13, 2015 at 10:36

7 votes

1 answer

251 views

Eigenvectors of a matrix with entries involving combinatorics

asked Nov 29, 2016 at 5:22

7 votes

0 answers

329 views

$n\varphi(n)\equiv 2\pmod{\sigma(n)}$ as a primality test

asked Nov 1, 2013 at 3:35

7 votes

2 answers

2k views

Applications of periodic continued fractions

asked Dec 20, 2010 at 4:47

6 votes

1 answer

595 views

Equal digit sums

asked Apr 19, 2012 at 13:15

6 votes

0 answers

288 views

Legendre polynomials and formal groups

asked Feb 4, 2015 at 13:10

6 votes

0 answers

436 views

On Fourier coefficients of nonnegative function

asked Nov 20, 2016 at 3:27

5 votes

2 answers

267 views

LDPC codes construction

asked Dec 20, 2016 at 10:29

5 votes

1 answer

932 views

On a sum involving Euler totient function

asked Jan 3, 2014 at 5:03

5 votes

0 answers

312 views

Elliptic curve sequences needed for universal forgery

asked Jan 15, 2018 at 6:24

4 votes

1 answer

527 views

Reference for inequality for $\sum\limits_{d \mid n}\frac{\log d}{d}.$

asked Jul 17, 2018 at 0:26

4 votes

1 answer

165 views

The number of solutions of the equation $ax_1x_2+by_1y_2=n$

asked Jul 27, 2018 at 7:06

4 votes

1 answer

170 views

Stationary phase method for $\varphi''(x_0)= 0$

asked Feb 24, 2020 at 11:50

Stack Exchange Network

46 Questions

Most intriguing mathematical epigraphs

Is there a regular pentagon with a rational point on each edge?

"The Two Sheriffs" puzzle

Solve in positive integers: $n!=m(m+1)$

Applications of finite continued fractions

The origin of Discrete `Liouville's theorem'

"Gauss trick" vs Karatsuba multiplication

Open problems in continued fractions theory

$\mathbb{R}^3$ as the union of disjoint circles

Limiting shape for Brillouin zones

“The Two Sheriffs” puzzle -2: threshold for security

What is the value of $p$-adic $\zeta$-function at positive integer point?

Lengths of continued fractions for the numbers with fixed ratio

2-adic Logarithm and Resistance of n-dimensional Cube

Yang–Baxter explanation

Is Somos-8 $\mod 2$ periodic?

De Bruijn sequence inside De Bruijn sequence

On one class of Somos-like sequences

Eigenvectors of a matrix with entries involving combinatorics

$n\varphi(n)\equiv 2\pmod{\sigma(n)}$ as a primality test

Applications of periodic continued fractions

Equal digit sums

Legendre polynomials and formal groups

On Fourier coefficients of nonnegative function

LDPC codes construction

On a sum involving Euler totient function

Elliptic curve sequences needed for universal forgery

Reference for inequality for $\sum\limits_{d \mid n}\frac{\log d}{d}.$

The number of solutions of the equation $ax_1x_2+by_1y_2=n$

Stationary phase method for $\varphi''(x_0)= 0$