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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 168 |
| 7 | 204 |
| 8 | 348 |
| 9 | 696 |
| 10 | 1601 |
| 11 | 3476 |
| 12 | 7244 |
| 13 | 14048 |
| 14 | 27164 |
| 15 | 54300 |
| 16 | 109741 |
| 17 | 223641 |
| 18 | 452621 |
| 19 | 908389 |
| 20 | 1822758 |
| 21 | 3657710 |
| 22 | 7359642 |
| 23 | 14825163 |
| 24 | 29845108 |
| 25 | 60064056 |
| 26 | 120806672 |
| 27 | 242986234 |
| 28 | 488854773 |
| 29 | 983578792 |
| 30 | 1979138437 |
| 31 | 3982088115 |
[1,2,6,24,120,168,204,348,696,1601,3476,7244, 14048,27164,54300,109741,223641,452621,908389, 1822758,3657710,7359642,14825163,29845108, 60064056,120806672,242986234,488854773,983578792, 1979138437,3982088115] |