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Questions where prime numbers play a key-role, such as: questions on the distribution of prime numbers (twin primes, gaps between primes, Hardy–Littlewood conjectures, etc); questions on prime numbers with special properties (Wieferich prime, Wolstenholme prime, etc.). This tag is often used as a specialized tag in combination with the top-level tag nt.number-theory and (if applicable) analytic-number-theory.

0 votes
1 answer
236 views

Is it consistent with Cramer's conjecture to conjecture that $x/\pi_{2}(x)>2B_{2}/6\times\lo...

Brun's constant $B_{2}$ is defined as $B_{2}=1/3+1/5+1/5+1/7+1/11+1/13+...$ where the sum is taken on $p$ such that $p$ is an element of a couple of twin primes. The number of twin primes below is exp …
Sylvain JULIEN's user avatar
0 votes
1 answer
250 views

Asymptotics for a peculiar kind of squarefree numbers

Let $ n $ denote a square free positive composite integer, $ \omega(n) $ its number of prime factors, $ P_{i}(n) $ its $ i $ -th prime factor. Can we determine an asymptotics for the number of …
Sylvain JULIEN's user avatar
2 votes
1 answer
972 views

About Extended Goldbach's conjecture

Hello, This question is a follow-up from About Goldbach's conjecture. As $N_{2}(n)=\sum_{r\leq n}1_{\mathbb{P}}(n-r)1_{\mathbb{P}}(n+r)$, Chebotarev's theorem allows to write: $$\dfrac{N_{2}(n)}{ …
Sylvain JULIEN's user avatar
2 votes

Is $\Bigl\{ n \sum_{k=2}^{n-1} \frac{1}{k}\Bigr\}$ unique $\forall n \in \Bbb{N}, n>1$

Only a partial answer for now, as it is too long for a comment. From my comment and Carlo Beenakker's answer, it suffices to consider the case where $n$ and $m$ have different radicals but the same pa …
Sylvain JULIEN's user avatar
6 votes

Constant $a$ such that $[a^n]$ is always prime for $n\in N^+$

Maybe not exactly what you're looking for, but in his book "Merveilleux nombres premiers" (in French), Jean-Paul Delahaye mentions the so-called Mills' constant $A=1.30637788386...$ which fulfills, un …
Sylvain JULIEN's user avatar
4 votes
2 answers
970 views

Lower bound for a prime gap occurring infinitely often

In his striking paper of may 2013, Zhang showed the existence of an even integer $g\lt 70,000,000$ such that $g$ is a prime gap occurring infinitely often. What is the best unconditional lower bound f …
Sylvain JULIEN's user avatar
6 votes
0 answers
726 views

Would the following conjectures imply Cramer's conjecture?

Assume Goldbach's conjecture. Then for every $n\ge 2$ there exists at least one non-negative integer $r\le n-2$ such that both $n+r$ and $n-r$ are primes. Let's write $r_{0}(n):=\inf\{r\le n-2, (n-r,n …
Sylvain JULIEN's user avatar
5 votes
1 answer
618 views

Has this strengthening of the PNT already been conjectured?

Suppose $f:\mathbb{Z}_{\geq 0}\to\mathbb{Z}_{\geq 0}$ is an arithmetic function that grows slower than the identity map. Has it already been conjectured that, under this general hypotheses, $\pi(n+f(n …
Sylvain JULIEN's user avatar
6 votes
1 answer
725 views

is there any heuristics suggesting that the number of Fibonacci primes below $x$ is equivale...

The question of knowing whether there are infinitely many Fibonacci primes is an open question. As $F_p$ is prime only if $p$ is prime, one has $\pi_{FP}(x)\le \pi(\log_{\phi} x+0.5\log 5)$, but numer …
Sylvain JULIEN's user avatar
11 votes
0 answers
2k views

Would the following conjectures imply $\lim\inf_{n\to\infty}p_{n+k}-p_{n}=O(k\log k)$?

Assume Goldbach's conjecture. Then for every $n\ge 2$ there exists at least one non-negative integer $r\le n-2$ such that both $n+r$ and $n-r$ are primes. Let's write $r_{0}(n):=\inf\{r\le n-2, (n-r,n …
Sylvain JULIEN's user avatar
-8 votes
1 answer
383 views

Is $2^{p}-1$ prime iff for $\frac{p-1}{2}$ odd positive integers $n$ below $p$, $(n+2)\vert ... [closed]

As I was playing around with Mersenne numbers, and discovered the notion of Wagstaff prime going off Wikipedia, I started considering the sequence, for a given $odd$ prime number $p$, defined as follo …
Sylvain JULIEN's user avatar
5 votes
1 answer
658 views

Does $0<k<n$ imply $p_{n+k}<\left(1+\frac{1}{k}\right)^k p_{n}$ for large enough $n$?

Disclaimer: a stronger version of this question was first asked on MSE: https://math.stackexchange.com/questions/3896547/does-p-nk1-frac1kk-p-n-whenever-0kn/3896842#3896842 and on a French math forum …
Sylvain JULIEN's user avatar
0 votes
0 answers
142 views

Expliciting the distance between consecutive Goldbach numbers assuming it's finite

In this paper, the author shows unconditionally that at least one of the following statements holds: i) the distance between two consecutive Goldbach numbers is finite, i.e. there exists an absolut …
Sylvain JULIEN's user avatar
0 votes
0 answers
140 views

Bounding $\dfrac{r(x)}{\pi(x+r(x))-\pi(x-r(x))}$ with $1\ll r(x)\ll \log^{4}(x)$

I would like to know whether it is possible to obtain the bounds $\sqrt{r(x)}\ll k(x)\ll r(x)$ where $k(x)={\pi(x+r(x))-\pi(x-r(x))}$ and $1\ll r(x)\ll \log^{4}(x)$ and thus $1\ll\dfrac{r(x)}{\pi(x+r( …
Sylvain JULIEN's user avatar
2 votes
1 answer
186 views

Integers whose product is a primorial and primality of their sum or difference

Let $ a $ and $ b $ be two positive integers such that $ a\lt b $ and $ ab $ is a primorial. Let $\mathcal{N}(x)=\mathcal{N}_{prime}(x)+\mathcal{N}_{pure}(x)+\mathcal{N}_{mixed}(x)$ where $ \m …
Sylvain JULIEN's user avatar

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