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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 87 |
| 11 | 504 |
| 12 | 4275 |
| 13 | 29433 |
| 14 | 179235 |
| 15 | 955818 |
| 16 | 4653802 |
| 17 | 21034628 |
| 18 | 89834238 |
| 19 | 366490378 |
| 20 | 1440743933 |
| 21 | 5493453262 |
[0,0,0,0,0,0,0,0,0,87,504,4275,29433,179235, 955818,4653802,21034628,89834238,366490378, 1440743933,5493453262] |