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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 9 |
| 10 | 44 |
| 11 | 108 |
| 12 | 222 |
| 13 | 431 |
| 14 | 900 |
| 15 | 1157 |
| 16 | 2258 |
| 17 | 1381 |
| 18 | 7429 |
| 19 | 5542 |
| 20 | 18306 |
| 21 | 22067 |
| 22 | 47849 |
| 23 | 10542 |
| 24 | 202169 |
| 25 | 28977 |
[0,0,0,0,0,0,0,1,9,44,108,222,431,900,1157,2258, 1381,7429,5542,18306,22067,47849,10542,202169, 28977] |