405000000domain: NAppears in sequencesNumber of n-digit numbers that yield an n-digit number after Reverse and Add.at n=8A232729Even positive integers whose canonical prime factorization p_1^e_1*...*p_r^e_r satisfies that {p_1, ..., p_r, e_1, ..., e_r} is a set of 2*r consecutive integers.at n=27A392046