9993999domain: NAppears in sequencesTerms of A088753 that are not terms of A063048.at n=6A089521Numbers k such that k multiplied by the sum of reciprocals of digits is the digit reversal of k.at n=30A309654a(n) = 10^(2n+1) - 1 - 6*10^n.at n=3A332193