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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 4 |
| 5 | 7 |
| 6 | 9 |
| 7 | 21 |
| 8 | 222 |
| 9 | 253 |
| 10 | 349 |
| 11 | 378 |
| 12 | 400 |
| 13 | 435 |
| 14 | 1153 |
| 15 | 1245 |
| 16 | 2052 |
| 17 | 2686 |
| 18 | 3724 |
| 19 | 4270 |
| 20 | 13095 |
| 21 | 21426 |
| 22 | 30265 |
| 23 | 36790 |
| 24 | 41758 |
[0,1,3,4,7,9,21,222,253,349,378,400,435,1153,1245, 2052,2686,3724,4270,13095,21426,30265,36790,41758] |