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| n | a(n) |
|---|---|
| -1 | 1 |
| 0 | 264 |
| 1 | 8244 |
| 2 | 139520 |
| 3 | 1672290 |
| 4 | 15872256 |
| 5 | 126745880 |
| 6 | 884100096 |
| 7 | 5525046495 |
| 8 | 31498809600 |
| 9 | 166049246340 |
| 10 | 817866616320 |
| 11 | 3794952949854 |
| 12 | 16699329285120 |
| 13 | 70071039813240 |
| 14 | 281650911606784 |
| 15 | 1088671630120515 |
| 16 | 4060062852952320 |
[1,264,8244,139520,1672290,15872256,126745880, 884100096,5525046495,31498809600,166049246340, 817866616320,3794952949854,16699329285120, 70071039813240,281650911606784,1088671630120515, 4060062852952320] |