Numbers obtained by adding the first k repdigits that consist of the same digit, for some number k.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =12a(10) =24a(11) =36a(12) =48a(13) =60a(14) =72a(15) =84a(16) =96a(17) =108a(18) =123a(19) =246a(20) =369a(21) =492a(22) =615a(23) =738a(24) =861a(25) =984a(26) =1107a(27) =1234a(28) =2468a(29) =3702