Words over an alphabet of size 9 that are in standard order with at least one letter repeated.

Terms

a(0) =11a(1) =111a(2) =112a(3) =121a(4) =122a(5) =1111a(6) =1112a(7) =1121a(8) =1122a(9) =1123a(10) =1211a(11) =1212a(12) =1213a(13) =1221a(14) =1222a(15) =1223a(16) =1231a(17) =1232a(18) =1233a(19) =11111a(20) =11112a(21) =11121a(22) =11122a(23) =11123a(24) =11211a(25) =11212a(26) =11213a(27) =11221a(28) =11222a(29) =11223