9560039domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that are congruent to -1 mod n, where n is the index of the prime.at n=19A052013Primes p such that pi(p) divides p-1 and/or p+1, where pi(p) is the number of primes <= p.at n=31A162567Prime numbersat n=637336