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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 20000 |
| 3 | 0 |
| 4 | 66680000 |
| 5 | 0 |
| 6 | 88977788000 |
| 7 | 0 |
| 8 | 63669939056000 |
| 9 | 0 |
| 10 | 28388261970800800 |
| 11 | 0 |
| 12 | 8645481416595304000 |
| 13 | 0 |
| 14 | 1913769409906455052000 |
| 15 | 0 |
| 16 | 322081772124335598304000 |
| 17 | 0 |
| 18 | 42639787126552298702388000 |
| 19 | 0 |
| 20 | 4560880160205473732557707200 |
| 21 | 0 |
| 22 | 402747462617285816887874972000 |
| 23 | 0 |
| 24 | 29887395794995795375534035536000 |
| 25 | 0 |
[1,0,20000,0,66680000,0,88977788000,0, 63669939056000,0,28388261970800800,0, 8645481416595304000,0,1913769409906455052000,0, 322081772124335598304000,0, 42639787126552298702388000,0, 4560880160205473732557707200,0, 402747462617285816887874972000,0, 29887395794995795375534035536000,0] |