User Konstantinos Gaitanas

35 votes

2 answers

3k views

Two polynomials which are "completely" coprime

asked Mar 21, 2023 at 10:42

31 votes

5 answers

8k views

Fermat's proof for $x^3-y^2=2$

asked Sep 15, 2013 at 14:50

21 votes

1 answer

773 views

Avoiding multiples of $p$

asked Nov 26, 2013 at 11:34

17 votes

3 answers

2k views

About the prime divisors of values of polynomials

asked Jun 6, 2015 at 16:53

16 votes

1 answer

1k views

Divergence of a series similar to $\sum\frac{1}{p}$

asked Jan 1, 2015 at 23:43

11 votes

3 answers

875 views

How many solutions does $\frac{1}{x_1}+\frac{1}{x_2}+\cdots +\frac{1}{x_n}=1$ have?

asked Jan 28, 2016 at 12:29

11 votes

3 answers

753 views

Does $2^n-n$ have infinitely often a prime divisor greater than $n$?

asked Nov 19, 2016 at 6:59

11 votes

1 answer

494 views

Which of these sums appear most often?

asked Jan 3, 2018 at 13:45

10 votes

0 answers

223 views

Product of four consecutive primes plus $1$ equals square

asked Mar 20, 2018 at 10:20

10 votes

1 answer

706 views

Primes dividing $2^a+2^b-1$

asked Jun 26, 2014 at 12:13

9 votes

2 answers

276 views

For which values of $k$ is it known that there are infinitely many $n$, such that $2^{n+k}\equiv 1\pmod{n}$?

asked Dec 19, 2017 at 10:10

8 votes

1 answer

416 views

Every odd integer greater than $1$ is of the form $a+b$ with $a^2+b^2$ being prime

asked Mar 27, 2018 at 20:23

7 votes

1 answer

304 views

Can a primitive root-permutation of $A=\{1, 2, \ldots, p-1 \}$ be a cycle of length $p-1$ only for finitely many $p$?

asked Jul 29, 2018 at 17:18

7 votes

2 answers

397 views

An equation involving perfect numbers

asked Jan 26, 2014 at 15:56

7 votes

3 answers

1k views

a question for the prime counting function

asked Aug 20, 2013 at 16:38

6 votes

3 answers

822 views

Is it possible to multiply two series to get as a result all composite numbers?

asked Feb 2, 2020 at 18:23

5 votes

1 answer

287 views

Is the factorization of $a_m-a_n$ affected by the fact that $\Sigma \frac{1}{a_k}<+\infty$?

asked Oct 16, 2020 at 7:22

5 votes

0 answers

974 views

$\sum_{n=1}^{\infty}\frac{1}{a_n}=\infty$ $\sum_{n=1}^{\infty}\frac{1}{b_n}=\infty$ but $\sum_{n=1}^{\infty}\frac{1}{a_n+b_n}=c, c\in R$ [closed]

asked Oct 6, 2013 at 20:23

5 votes

0 answers

239 views

The sum of all the elements of every non empty subset of $A$ is not a multiple of $n$

asked Oct 30, 2014 at 21:35

3 votes

1 answer

240 views

Is $2^n -1$ finitely many times the product of consecutive primes? [duplicate]

asked Oct 10, 2015 at 7:44

3 votes

1 answer

309 views

How to estimate the sum $\sum_{n\le x} \frac{n}{\tau(n)}$?

asked Oct 30, 2019 at 9:12

2 votes

1 answer

80 views

Chain of sequences, such that $a_{k+1}(n)$ completes $a_k(n)$

asked Oct 22, 2019 at 10:18

2 votes

2 answers

804 views

prime zeta function when $0<s<1$ [closed]

asked Feb 21, 2014 at 21:44

1 vote

3 answers

4k views

Number of subsets with fixed cardinality k, and sum of elements a multiple of m

asked Sep 11, 2013 at 22:14

1 vote

1 answer

328 views

Radical of the sum $=$ radical of the product

asked Nov 10, 2015 at 10:35

1 vote

0 answers

390 views

Is there a "complete" Sidon sequence?

asked Nov 17, 2015 at 10:14

1 vote

0 answers

71 views

On the sum of digits of primes in binary form [duplicate]

asked Jan 25, 2016 at 10:45

1 vote

1 answer

81 views

Reference request for multiple free sequences

asked Aug 19, 2017 at 17:05

1 vote

2 answers

719 views

Numbers greater than Skewes's whose existence can be found in number theoretic proofs

asked Mar 9, 2015 at 17:00

1 vote

0 answers

98 views

Reference request for a result in additive combinatorics

asked Oct 18, 2022 at 10:46

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32 Questions

Two polynomials which are "completely" coprime

Fermat's proof for $x^3-y^2=2$

Avoiding multiples of $p$

About the prime divisors of values of polynomials

Divergence of a series similar to $\sum\frac{1}{p}$

How many solutions does $\frac{1}{x_1}+\frac{1}{x_2}+\cdots +\frac{1}{x_n}=1$ have?

Does $2^n-n$ have infinitely often a prime divisor greater than $n$?

Which of these sums appear most often?

Product of four consecutive primes plus $1$ equals square

Primes dividing $2^a+2^b-1$

For which values of $k$ is it known that there are infinitely many $n$, such that $2^{n+k}\equiv 1\pmod{n}$?

Every odd integer greater than $1$ is of the form $a+b$ with $a^2+b^2$ being prime

Can a primitive root-permutation of $A=\{1, 2, \ldots, p-1 \}$ be a cycle of length $p-1$ only for finitely many $p$?

An equation involving perfect numbers

a question for the prime counting function

Is it possible to multiply two series to get as a result all composite numbers?

Is the factorization of $a_m-a_n$ affected by the fact that $\Sigma \frac{1}{a_k}<+\infty$?

$\sum_{n=1}^{\infty}\frac{1}{a_n}=\infty$ $\sum_{n=1}^{\infty}\frac{1}{b_n}=\infty$ but $\sum_{n=1}^{\infty}\frac{1}{a_n+b_n}=c, c\in R$ [closed]

The sum of all the elements of every non empty subset of $A$ is not a multiple of $n$

Is $2^n -1$ finitely many times the product of consecutive primes? [duplicate]

How to estimate the sum $\sum_{n\le x} \frac{n}{\tau(n)}$?

Chain of sequences, such that $a_{k+1}(n)$ completes $a_k(n)$

prime zeta function when $0<s<1$ [closed]

Number of subsets with fixed cardinality k, and sum of elements a multiple of m

Radical of the sum $=$ radical of the product

Is there a "complete" Sidon sequence?

On the sum of digits of primes in binary form [duplicate]

Reference request for multiple free sequences

Numbers greater than Skewes's whose existence can be found in number theoretic proofs

Reference request for a result in additive combinatorics