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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 3 |
| 3 | 2 |
| 4 | 21 |
| 5 | 35 |
| 6 | 209 |
| 7 | 547 |
| 8 | 2585 |
| 9 | 8547 |
| 10 | 36796 |
| 11 | 137022 |
| 12 | 572823 |
| 13 | 2267281 |
| 14 | 9451024 |
| 15 | 38678305 |
| 16 | 162279625 |
| 17 | 677816640 |
| 18 | 2869255664 |
| 19 | 12153326315 |
| 20 | 51898954441 |
| 21 | 222150734758 |
| 22 | 956193664648 |
| 23 | 4127336568163 |
| 24 | 17888946954832 |
| 25 | 77752439126691 |
| 26 | 339049643912001 |
| 27 | 1482310626668551 |
| 28 | 6498203118707345 |
[1,0,3,2,21,35,209,547,2585,8547,36796,137022, 572823,2267281,9451024,38678305,162279625, 677816640,2869255664,12153326315,51898954441, 222150734758,956193664648,4127336568163, 17888946954832,77752439126691,339049643912001, 1482310626668551,6498203118707345] |