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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 48 |
| 3 | 288 |
| 4 | 1280 |
| 5 | 4800 |
| 6 | 16128 |
| 7 | 50176 |
| 8 | 147456 |
| 9 | 414720 |
| 10 | 1126400 |
| 11 | 2973696 |
| 12 | 7667712 |
| 13 | 19382272 |
| 14 | 48168960 |
| 15 | 117964800 |
| 16 | 285212672 |
| 17 | 681836544 |
| 18 | 1613758464 |
| 19 | 3785359360 |
| 20 | 8808038400 |
| 21 | 20346568704 |
| 22 | 46690992128 |
| 23 | 106501767168 |
| 24 | 241591910400 |
[4,48,288,1280,4800,16128,50176,147456,414720, 1126400,2973696,7667712,19382272,48168960, 117964800,285212672,681836544,1613758464, 3785359360,8808038400,20346568704,46690992128, 106501767168,241591910400] |