0
$\begingroup$

Let $p$ be a prime. Are there infinitely many prime numbers which are of the form $p$$^2$$+$$4$?

$\endgroup$
12
  • 1
    $\begingroup$ Where is your attempt? $\endgroup$
    – tien lee
    Commented Jul 15, 2018 at 3:30
  • $\begingroup$ Welcome to MSE! Your question will likely be better received if you show what you have tried to resolve the problem, and/or the context of the problem. $\endgroup$
    – Sambo
    Commented Jul 15, 2018 at 3:33
  • $\begingroup$ I just put that, thank you. $\endgroup$
    – Pacifica
    Commented Jul 15, 2018 at 3:48
  • $\begingroup$ $p^2+4 \equiv -1(\mod 6)$ only implies that if there are infintely or finitely many primes of the form $p^2+4$, then all of them will leave a remainder $5$ when divided by $6$. $\endgroup$ Commented Jul 15, 2018 at 4:31
  • 1
    $\begingroup$ Alright, I deleted it. $\endgroup$
    – Pacifica
    Commented Jul 15, 2018 at 5:03

1 Answer 1

5
$\begingroup$

The easy answer: We don't know.

Check out: https://oeis.org/A045637.

It looks like this problem is open but an answer would follow from us resolving the Bunyakovsky conjecture. You can read up on that here or on wiki.

$\endgroup$
1
  • $\begingroup$ This is a field which has full of conjectures. $\endgroup$
    – Pacifica
    Commented Jul 15, 2018 at 6:59

Not the answer you're looking for? Browse other questions tagged .