111131111domain: NAppears in sequencesPalindromes for which the product of the digits is prime.at n=17A117058Composite numbers with digital product = 3.at n=21A199982Composite numbers for which both sum and product of digits are primes.at n=30A225864a(n) = (10^(2*n+1) - 1)/9 + 2*10^n.at n=4A332113