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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 77 |
| 6 | 497 |
| 7 | 3676 |
| 8 | 30677 |
| 9 | 285335 |
| 10 | 2928846 |
| 11 | 32903721 |
| 12 | 401739797 |
| 13 | 5298600772 |
| 14 | 75092880273 |
| 15 | 1138261010851 |
| 16 | 18378421938366 |
| 17 | 314928827507717 |
| 18 | 5708689036074089 |
| 19 | 109145365739197964 |
| 20 | 2195167574579322013 |
| 21 | 46331767712354136479 |
| 22 | 1023970009016490622478 |
[1,0,1,3,14,77,497,3676,30677,285335,2928846, 32903721,401739797,5298600772,75092880273, 1138261010851,18378421938366,314928827507717, 5708689036074089,109145365739197964, 2195167574579322013,46331767712354136479, 1023970009016490622478] |