321203domain: NPropertiesPrimalityPrimeyesAppears in sequencesPseudoprimes to base 4, written in base 4.at n=26A262101Primes p whose binary representation p_2 is the decimal representation of a prime q; and also the sum of the decimal digits of p equals the sum of the digits of p_2.at n=20A281299Prime numbersat n=27704