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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 36 |
| 2 | 720 |
| 3 | 10560 |
| 4 | 126720 |
| 5 | 1317888 |
| 6 | 12300288 |
| 7 | 105431040 |
| 8 | 843448320 |
| 9 | 6372720640 |
| 10 | 45883588608 |
| 11 | 317013884928 |
| 12 | 2113425899520 |
| 13 | 13655982735360 |
| 14 | 85837605765120 |
| 15 | 526470648692736 |
| 16 | 3158823892156416 |
| 17 | 18581317012684800 |
| 18 | 107358720517734400 |
| 19 | 610249569258700800 |
[1,36,720,10560,126720,1317888,12300288,105431040, 843448320,6372720640,45883588608,317013884928, 2113425899520,13655982735360,85837605765120, 526470648692736,3158823892156416, 18581317012684800,107358720517734400, 610249569258700800] |