a(n) = the number of ways in which n is equal to the sum of digits > 0 taken from numbers <= n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =3a(5) =4a(6) =5a(7) =6a(8) =8a(9) =17a(10) =53a(11) =158a(12) =450a(13) =1224a(14) =3195a(15) =8036a(16) =19585a(17) =46549a(18) =108541a(19) =219677a(20) =664149a(21) =1891075a(22) =5091680a(23) =13004347a(24) =31632641a(25) =73745789a(26) =166055768a(27) =364027232a(28) =782374631a(29) =1462836178