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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 0 |
| 6 | 20 |
| 7 | 0 |
| 8 | 1 |
| 9 | 1680 |
| 10 | 0 |
| 11 | 330 |
| 12 | 369600 |
| 13 | 1 |
| 14 | 180180 |
| 15 | 168168000 |
| 16 | 13990 |
| 17 | 163363200 |
| 18 | 137225088001 |
| 19 | 39041010 |
| 20 | 232792560000 |
| 21 | 182509367449640 |
| 22 | 118574979600 |
| 23 | 494730748512001 |
| 24 | 369398970833730090 |
| 25 | 451334037000000 |
| 26 | 1500683270499930350 |
| 27 | 1080492079984609149000 |
[1,0,0,1,0,0,20,0,1,1680,0,330,369600,1,180180, 168168000,13990,163363200,137225088001,39041010, 232792560000,182509367449640,118574979600, 494730748512001,369398970833730090, 451334037000000,1500683270499930350, 1080492079984609149000] |