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Timeline for Primes of the form $d^2+d+1$

Current License: CC BY-SA 4.0

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Jan 19, 2023 at 11:03 vote accept numberwat
Jan 18, 2023 at 17:13 comment added Sylvain JULIEN I guess so, that's the goal actually. An approach through dynamic systems might be fruitful. I have the vague idea that this could be related to hypothetical "n-th roots of automorphisms" i.e. maps $g$ such that $g^{\circ n}$ is an automorphism.
Jan 18, 2023 at 17:05 comment added Steven Stadnicki @SylvainJULIEN Wouldn't that immediately imply this specific case of Bunyanakovsky?
Jan 18, 2023 at 17:02 comment added Sylvain JULIEN It might be interesting to restrict oneself to the case where $d$ is itself prime and study the images of the iterates of $f:x\mapsto x^2+x+1$, for example trying to establish that for infinitely many primes $p$, there exists an integer $k_{p}$ such that $f^{\circ k_{p}}(p)$ is prime.
Jan 18, 2023 at 15:45 answer added Stanley Yao Xiao timeline score: 7
Jan 18, 2023 at 15:12 history edited Steven Landsburg CC BY-SA 4.0
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Jan 18, 2023 at 14:32 comment added Fedor Petrov I am afraid that it is not even known whether a polynomial of degree more than 1 for which it holds exists
Jan 18, 2023 at 14:13 comment added Wlod AA In the given context it's good to recall en.wikipedia.org/wiki/Friedlander%E2%80%93Iwaniec_theorem.
Jan 18, 2023 at 13:45 comment added Boaz Moerman @JoséHdz.Stgo. This is true for every polynomial though, so it is not a special property of this one. This is for example shown in the answer to math.stackexchange.com/questions/86018/….
Jan 18, 2023 at 13:40 comment added José Hdz. Stgo. At least you can prove that if $X$ is an integer greater that $1$ such that $p(X)$ is a prime number then $X \equiv 0 \pmod{3}$ or $X \equiv 1 \pmod{3}$: in other words, the polynomial does produce infinitely many composite numbers.
Jan 18, 2023 at 13:40 comment added Boaz Moerman As mentioned in the section "Partial results: only Dirichlet's theorem" of the Wikipedia page you linked, this is only known for linear polynomials, and for no others.
Jan 18, 2023 at 13:33 comment added YCor I think there is no polynomial of degree $\ge 2$ for which this is known to hold.
Jan 18, 2023 at 13:28 history asked numberwat CC BY-SA 4.0