205589domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that remain prime through 4 iterations of function f(x) = 3x + 2.at n=13A023307Numbers being the smallest positive integer having its digits (Cf. A179239) from which two digits can be chosen, the difference being any value from 0 to 9.at n=12A365375Prime numbersat n=18434