11221211domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that contain digits 1 and 2 only.at n=22A020450Smallest n-digit prime containing only digits 1 or 2 or -1 if no such prime exists.at n=7A036229Primes with digital product = 8.at n=28A107694Successive generations of an alternating Kolakoski rule.at n=6A111081Prime numbersat n=740177