307397domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes p such that phi(p-2) = phi(p-1).at n=11A256510Primes p such that phi(phi(p-1)+1) = phi(phi(p-2)+1).at n=27A271659Primes p such that phi(phi(p-2)-1) = phi(phi(p-1)-1).at n=16A271660Prime numbersat n=26605