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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 27 |
| 5 | 328 |
| 6 | 1995 |
| 7 | 2323 |
| 8 | 6641 |
| 9 | 8964 |
| 10 | 544481 |
| 11 | 553445 |
| 12 | 1651371 |
| 13 | 2204816 |
| 14 | 14880267 |
| 15 | 180768020 |
| 16 | 1099488387 |
| 17 | 1280256407 |
| 18 | 3660001201 |
| 19 | 4940257608 |
| 20 | 300075457681 |
| 21 | 305015715289 |
| 22 | 910106888259 |
| 23 | 1215122603548 |
| 24 | 8200842509547 |
| 25 | 99625232718112 |
| 26 | 605952238818219 |
[1,1,3,4,27,328,1995,2323,6641,8964,544481,553445, 1651371,2204816,14880267,180768020,1099488387, 1280256407,3660001201,4940257608,300075457681, 305015715289,910106888259,1215122603548, 8200842509547,99625232718112,605952238818219] |