9
$\begingroup$

Are there consecutive gaps(difference) of 4 between prime numbers?

Seeing at the first few gaps
$1, 2, 2, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 6, 6, 2, 6, 4, 2, 6,.....$. (for example 6 is repeated consecutively at some places).

Are there consecutive gaps of 4 between prime numbers?

If there is no twin gap of 4, then how to prove it, what is the proof of that?

$\endgroup$
13
$\begingroup$

One of $\{p,p+4,p+8\}$ will be divisible by $3$, so if they are all to be primes, one of them must be $3$ itself. Then we have $3,7,11$, which are all prime, but unfortunately 3 to 7 is not a gap, so no, there cannot be two consecutive prime gaps of length 4.

$\endgroup$
2
$\begingroup$

Just to elaborate on @Henning Makholm's answer:

  • $p\equiv0\pmod3 \implies p=3 \implies p+4\neq5\text{ which is the next prime}$
  • $p\equiv1\pmod3 \implies p+8\equiv9\equiv0\pmod3 \implies p+8\text{ is not prime}$
  • $p\equiv2\pmod3 \implies p+4\equiv6\equiv0\pmod3 \implies p+4\text{ is not prime}$
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy