75308643domain: NAppears in sequencesThe differences 1-1, 21-12, 321-123, ..., 10987654321-12345678910, 1110987654321-1234567891011, etc.at n=7A019566Numbers belonging to cycles of length 7 under the Kaprekar map A151949.at n=9A164729a(n) = Sum_{i=0..n-1} i*10^i - Sum_{i=0..n-1} (n-1-i)*10^i.at n=7A338226