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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 17 |
| 2 | 408 |
| 3 | 12648 |
| 4 | 480624 |
| 5 | 21628080 |
| 6 | 1124660160 |
| 7 | 66354949440 |
| 8 | 4379426663040 |
| 9 | 319698146401920 |
| 10 | 25575851712153600 |
| 11 | 2225099098957363200 |
| 12 | 209159315301992140800 |
| 13 | 21125090845501206220800 |
[1,17,408,12648,480624,21628080,1124660160, 66354949440,4379426663040,319698146401920, 25575851712153600,2225099098957363200, 209159315301992140800,21125090845501206220800] |