483611domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that (3^k - 1)/2 is prime.at n=16A028491Numbers n such that 3^n has the form 2p-+1 where p is prime.at n=22A096723Primes arising from A249567.at n=24A249568Prime numbersat n=40286