Q:

$28$ th largest known prime missing in the prime page database?

If I here
https://primes.utm.edu/primes/search.php
enter $30$ at the last field, I should get the $30$ largest known primes. Apparently, the $28$ th largest known prime is missing. Is this an error in the database , or do I miss something ?

A:

It is a glitch in the way the primes are pulled out of the database. Download the list of the top 5000. You get:
$26:  3*2^{11484018}-1$
$27:  193997*2^{11452891}+1$
$28: 2877652^{524288}+1$
$29: 2788032^{524288}+1$
$30:  2733014^{524288}+1$
Same primes, but now correctly labelled.

