Numbers k equal to the number of 1's in the decimal digits of all numbers <= k.

Terms

a(0) =0a(1) =1a(2) =199981a(3) =199982a(4) =199983a(5) =199984a(6) =199985a(7) =199986a(8) =199987a(9) =199988a(10) =199989a(11) =199990a(12) =200000a(13) =200001a(14) =1599981a(15) =1599982a(16) =1599983a(17) =1599984a(18) =1599985a(19) =1599986a(20) =1599987a(21) =1599988a(22) =1599989a(23) =1599990a(24) =2600000a(25) =2600001a(26) =13199998a(27) =35000000