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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 24 |
| 4 | 120 |
| 5 | 570 |
| 6 | 2850 |
| 7 | 14100 |
| 8 | 70500 |
| 9 | 351750 |
| 10 | 1758750 |
| 11 | 8790000 |
| 12 | 43950000 |
| 13 | 219731250 |
| 14 | 1098656250 |
| 15 | 5493187500 |
| 16 | 27465937500 |
| 17 | 137329218750 |
| 18 | 686646093750 |
| 19 | 3433228125000 |
| 20 | 17166140625000 |
| 21 | 85830691406250 |
| 22 | 429153457031250 |
| 23 | 2145767226562500 |
| 24 | 10728836132812500 |
| 25 | 53644180371093750 |
[1,6,24,120,570,2850,14100,70500,351750,1758750, 8790000,43950000,219731250,1098656250,5493187500, 27465937500,137329218750,686646093750, 3433228125000,17166140625000,85830691406250, 429153457031250,2145767226562500, 10728836132812500,53644180371093750] |