| n | a(n) |
|---|---|
| 0 | 220 |
| 1 | 221 |
| 2 | 1220 |
| 3 | 1221 |
| 4 | 2200 |
| 5 | 2201 |
| 6 | 2210 |
| 7 | 2211 |
| 8 | 10220 |
| 9 | 10221 |
| 10 | 11220 |
| 11 | 11221 |
| 12 | 12200 |
| 13 | 12201 |
| 14 | 12210 |
| 15 | 12211 |
| 16 | 22000 |
| 17 | 22001 |
| 18 | 22010 |
| 19 | 22011 |
| 20 | 22100 |
| 21 | 22101 |
| 22 | 22110 |
| 23 | 22111 |
| 24 | 22220 |
| 25 | 22221 |
| 26 | 23020 |
| 27 | 23021 |
| 28 | 33300 |
| 29 | 33301 |
| 30 | 33310 |
| 31 | 33311 |
| 32 | 100220 |
| 33 | 100221 |
| 34 | 101220 |
[220,221,1220,1221,2200,2201,2210,2211,10220, 10221,11220,11221,12200,12201,12210,12211,22000, 22001,22010,22011,22100,22101,22110,22111,22220, 22221,23020,23021,33300,33301,33310,33311,100220, 100221,101220] |