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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 213 |
| 10 | 38970 |
| 11 | 2199243 |
| 12 | 66436204 |
| 13 | 1334964325 |
| 14 | 20003126222 |
| 15 | 239548888455 |
[0,0,0,0,0,0,0,0,213,38970,2199243,66436204, 1334964325,20003126222,239548888455] |