789881domain: NAppears in sequencesIccanobirt numbers (14 of 15): a(n) = R(R(a(n-1)) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086.at n=22A102124Iccanobirt semiprimes (14 of 15): Semiprime numbers in A102124.at n=3A102204