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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 5 |
| 5 | 36 |
| 6 | 61 |
| 7 | 624 |
| 8 | 1385 |
| 9 | 18256 |
| 10 | 50521 |
| 11 | 814144 |
| 12 | 2702765 |
| 13 | 51475776 |
| 14 | 199360981 |
| 15 | 4381112064 |
| 16 | 19391512145 |
| 17 | 482962852096 |
| 18 | 2404879675441 |
| 19 | 66942218896384 |
| 20 | 370371188237525 |
| 21 | 11394877025289216 |
| 22 | 69348874393137901 |
| 23 | 2336793875186479104 |
| 24 | 15514534163557086905 |
[1,1,1,4,5,36,61,624,1385,18256,50521,814144, 2702765,51475776,199360981,4381112064,19391512145, 482962852096,2404879675441,66942218896384, 370371188237525,11394877025289216, 69348874393137901,2336793875186479104, 15514534163557086905] |