228281domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes p such that p,q,r,s are consecutive primes and 2p+9, 2q+9, 2r+9, 2s+9 are also primes.at n=31A190354Primes p with same last three digits as k, where prime(k) = p.at n=15A232104Prime numbersat n=20281