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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 9 |
| 3 | 107 |
| 4 | 450 |
| 5 | 450 |
| 6 | 67678 |
| 7 | 655923 |
| 8 | 2303009 |
| 9 | 13832611 |
| 10 | 54186218 |
| 11 | 1749037712 |
| 12 | 13612998170 |
| 13 | 27454285371 |
| 14 | 124343295778 |
| 15 | 4193681732872 |
| 16 | 18436366262701 |
| 17 | 217833949680307 |
| 18 | 1380986519616342 |
| 19 | 3009400117526791 |
| 20 | 3009400117526791 |
| 21 | 162593932712750793 |
| 22 | 3513869117212454835 |
[0,2,9,107,450,450,67678,655923,2303009,13832611, 54186218,1749037712,13612998170,27454285371, 124343295778,4193681732872,18436366262701, 217833949680307,1380986519616342,3009400117526791, 3009400117526791,162593932712750793, 3513869117212454835] |