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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 7 |
| 10 | 51 |
| 11 | 361 |
| 12 | 2484 |
| 13 | 16749 |
| 14 | 113662 |
| 15 | 784390 |
| 16 | 5517476 |
| 17 | 39291974 |
| 18 | 280215385 |
| 19 | 1979345466 |
| 20 | 13726798428 |
| 21 | 92895863119 |
| 22 | 611213599093 |
| 23 | 3902188079125 |
| 24 | 24154847660481 |
| 25 | 144967854078943 |
[0,0,0,0,0,0,0,1,7,51,361,2484,16749,113662, 784390,5517476,39291974,280215385,1979345466, 13726798428,92895863119,611213599093, 3902188079125,24154847660481,144967854078943] |