2822717domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes p such that phi(p-2) = phi(p-1).at n=16A256510Primes p such that phi(phi(p-1)+1) = phi(phi(p-2)+1).at n=37A271659Primes p such that phi(phi(p-2)-1) = phi(phi(p-1)-1).at n=26A271660Prime numbersat n=204941