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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 6 |
| 5 | 11 |
| 6 | 29 |
| 7 | 71 |
| 8 | 179 |
| 9 | 505 |
| 10 | 1405 |
| 11 | 4128 |
| 12 | 12639 |
| 13 | 39268 |
| 14 | 127059 |
| 15 | 420281 |
| 16 | 1423787 |
| 17 | 4955200 |
| 18 | 17579398 |
| 19 | 63796635 |
| 20 | 236161396 |
| 21 | 890544028 |
| 22 | 3422553065 |
| 23 | 13377869976 |
| 24 | 53184706291 |
| 25 | 214870633711 |
| 26 | 881485304157 |
| 27 | 3671033616614 |
| 28 | 15507956547021 |
| 29 | 66429816610908 |
[1,1,1,3,6,11,29,71,179,505,1405,4128,12639,39268, 127059,420281,1423787,4955200,17579398,63796635, 236161396,890544028,3422553065,13377869976, 53184706291,214870633711,881485304157, 3671033616614,15507956547021,66429816610908] |