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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 26 |
| 5 | 149 |
| 6 | 1024 |
| 7 | 7965 |
| 8 | 68192 |
| 9 | 632724 |
| 10 | 6294190 |
| 11 | 66579501 |
| 12 | 744194484 |
| 13 | 8747497833 |
| 14 | 107718981328 |
| 15 | 1385436413289 |
| 16 | 18563761993762 |
| 17 | 258579817821799 |
| 18 | 3737335096804136 |
| 19 | 55957031888334621 |
| 20 | 866632465992896412 |
| 21 | 13865193902724224273 |
| 22 | 228875892203793317404 |
| 23 | 3893773927147402337094 |
[1,1,2,6,26,149,1024,7965,68192,632724,6294190, 66579501,744194484,8747497833,107718981328, 1385436413289,18563761993762,258579817821799, 3737335096804136,55957031888334621, 866632465992896412,13865193902724224273, 228875892203793317404,3893773927147402337094] |