- 2 is a prime. 3 is the next prime. 23 is also a prime.
- 31 is a prime. 37 is the next prime. 3137 is also a prime.
Can we estimate or prove how many $XY$ are prime if $X$ and $Y$ are primes nr $n$ and $n+1$?
I know this is dependent on basis. I will for this question assume basis 10.
(Optional question) Can we prove whether lower or higher basis will increase or decrease occurrance?