209401domain: NPropertiesPrimalityPrimeyesAppears in sequencesSmaller of two consecutive prime numbers such that p1*p2*d - d = average of twin prime pairs, d (delta) = p2 - p1.at n=31A153378Primes 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=16A376605Prime numbersat n=18755