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10 votes
0 answers
416 views

Are prime numbers among sums of prime numbers distributed as $\frac n{2\ln(n)}$?

Let $(s_n)_{n\in\mathbb N}$ be defined as follows: For $n\in\mathbb N$, $s_n:=2+3+5+\cdots+p_n$ is the sum of the first $n$ prime numbers (e.g.: $s_1=2$, $s_2=5$, $s_3=10$, $s_4=17$, $\ldots$). Let $\...
Tobias Schnieders's user avatar
8 votes
2 answers
393 views

Can exist a positive integer number $x$ such that $a_1=x$ and $a_n=2a_{n-1}+1$ are not prime for all $n \ge 1$?

Using my computer, I found that the most of positive integer number $x$ such that $a_1=x$ and $a_n=2a_{n-1}+1$ is prime number after a few iterations. But exist some positive integer numbers, my ...
Đào Thanh Oai's user avatar
5 votes
0 answers
340 views

On a conjecture about the arithmetic function that counts the number of twin primes

This is cross-posted from the question that I've asked with same title on Mathematics Stack Exchange two months ago, which has remained unanswered. Given a positive real number $x$ we will write ...
user142929's user avatar
4 votes
1 answer
531 views

Do prime gaps that are a power of "h" have the same density?

Send me back to Mathematics Stack Exchange if this question is not research level. At Terence Tao's blog post there is the expression: $$\sum\limits_{n \leq X} \Lambda(n)\Lambda(n+h) \ \ \ \ \ \ \ \ \ ...
Mats Granvik's user avatar
  • 1,183
4 votes
1 answer
954 views

Arithmetic properties of a sum related to the first Hardy-Littlewood conjecture

The starting point of this post is an earlier question, where I conjectured (and GH from MO confirmed) that the von Mangoldt function is the limit at $s=1$ of a certain Dirichlet series, $$\Lambda(m)=\...
Mats Granvik's user avatar
  • 1,183
1 vote
1 answer
327 views

Symmetry in Hardy-Littlewood k-tuple conjecture

Assuming Hardy-Littlewood $k$-tuple conjecture, do the "dual" prime constellations $(0,h_1, h_2,\cdots, h_i,\cdots, h_{k-1}=d)$ and $(0, h_{k-1}-h_{k-2}, h_{k-1}-h_{k-3},\cdots,h'_i=h_{k-1}-...
Sylvain JULIEN's user avatar
1 vote
0 answers
96 views

Are the elements in the n-th row of the first matrix a permutation of the elements in the n-th row of the second matrix?

From my previous questions here and here the following two matrices arise for twin primes and cousin primes from Dirichlet convolution: For $h=2$ twin primes: $$T_2(n,m)=\sum\limits_{\substack{k=1 \\...
Mats Granvik's user avatar
  • 1,183
0 votes
1 answer
148 views

On the quantity of twin prime pairs of a given form

Let $p_l$ the $l$-th prime number. I've considered the formula $$\frac{N_{n+1}}{N_n}+\frac{N_{n+2}}{p_{n+1}N_n}\pm1$$ where $N_k=\prod_{l=1}^k p_l$ is the primorial of order $k$. Previous formula ...
user142929's user avatar
0 votes
2 answers
317 views

On a coprime generalization of Cramer's conjecture

Given a large enough integer $n\in\Bbb N$ and a real $r\in\big(0,\frac12\big]$ and $n_1\in\Bbb N_{> n}$ is the smallest integer such that $n_1=AB$ for two coprime integers $A$ bigger than but close ...
user avatar
0 votes
1 answer
154 views

Sergei numbers : even integers n being a prime gap at least n times

Let's introduce Sergei (for SElf-Referential Gaps Extensible to Infinity, and as a wink to a mathematician friend of mine of Russian descent whose given name is Serge and quite interested in number ...
Sylvain JULIEN's user avatar
0 votes
0 answers
177 views

Is there a link between Elliott-Halberstam and weak Hardy-Littlewood-Goldbach conjectures?

Let $\theta$ be such that $EH(\theta)$ holds, where $EH$ stands for Elliott-Halberstam. Can one get an explicit lower bound $\delta_{\theta}$ for the quantity $\delta$ appearing in the weak Hardy-...
Sylvain JULIEN's user avatar
-3 votes
1 answer
245 views

Can this weakening of Polignac's conjecture be proven?

Let $ A $ be a set of odd primes such that between any two consecutive elements thereof there is at least one prime gap that occurs infinitely often, i.e. an even integer $ g $ such that the ...
Sylvain JULIEN's user avatar