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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 45 |
| 4 | 1098 |
| 5 | 86800 |
| 6 | 3882992 |
| 7 | 199692576 |
| 8 | 10078711072 |
| 9 | 1696870266800 |
| 10 | 145139567193300 |
| 11 | 13546296060670325 |
| 12 | 1187049535139072700 |
| 13 | 119750974794907122850 |
| 14 | 11360997964869380793175 |
| 15 | 1099198326991641651851775 |
[1,0,45,1098,86800,3882992,199692576,10078711072, 1696870266800,145139567193300,13546296060670325, 1187049535139072700,119750974794907122850, 11360997964869380793175,1099198326991641651851775] |