SuperCthulhu, a member of the team BOINC@AUSTRALIA found a megaprime for base R298.
The prime 105*298^461505-1 has 1.141.866 digits and entered the TOP5000 in Chris Caldwell's The Largest Known Primes Database.
Source: https://srbase.my-firewall.org/sr5/foru ... hp?id=1819