218521domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes p such that each of the numbers p^k for k=1..5 has exactly two 1s in its decimal representation.at n=21A175964Primes p such that if q and r are the next two primes, (p - 1)^2 + 1, (q - 1)^2 + 1 and (r - 1)^2 + 1 are all prime.at n=17A376605Prime numbersat n=19484