The third challenge of the 2021 Series will be a 3-day challenge celebrating the 60th anniversary of Yuri Gagarin's history-making venture into outer space. The challenge will be offered on the WW application, beginning 11 April 18:00 UTC and ending 14 April 18:00 UTC.
This is a relatively new subproject here at PrimeGrid, and there are currently no known Wall–Sun–Sun primes! You could be the first to find one!
To participate in the Challenge, please select only the Wieferich and Wall-Sun-Sun Prime Search (WW) project in your PrimeGrid preferences section.
Questions? Queries? Quips? Discuss on the forum thread for this challenge. Best of luck!