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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 3 |
| 6 | 2 |
| 7 | 1 |
| 8 | 38 |
| 9 | 1080 |
| 10 | 14040 |
| 11 | 85500 |
| 12 | 274104 |
| 13 | 493920 |
| 14 | 504000 |
| 15 | 272160 |
| 16 | 60480 |
| 17 | 1 |
| 18 | 3502 |
| 19 | 9743106 |
| 20 | 3017318368 |
| 21 | 249756082950 |
| 22 | 8612276962188 |
| 23 | 156010151929968 |
| 24 | 1699145259725088 |
| 25 | 12107373916276800 |
| 26 | 59649257217110400 |
| 27 | 210765408910721280 |
| 28 | 546882291784604160 |
| 29 | 1056321717817766400 |
[1,1,3,3,2,1,38,1080,14040,85500,274104,493920, 504000,272160,60480,1,3502,9743106,3017318368, 249756082950,8612276962188,156010151929968, 1699145259725088,12107373916276800, 59649257217110400,210765408910721280, 546882291784604160,1056321717817766400] |