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| n | a(n) |
|---|---|
| 1 | 48 |
| 2 | 260 |
| 3 | 1408 |
| 4 | 7632 |
| 5 | 41344 |
| 6 | 224064 |
| 7 | 1213952 |
| 8 | 6578432 |
| 9 | 35643392 |
| 10 | 193143808 |
| 11 | 1046528000 |
| 12 | 5670785024 |
| 13 | 30726979584 |
| 14 | 166497435648 |
| 15 | 902168182784 |
| 16 | 4888469241856 |
| 17 | 26488322654208 |
| 18 | 143528684683264 |
| 19 | 777716068515840 |
[48,260,1408,7632,41344,224064,1213952,6578432, 35643392,193143808,1046528000,5670785024, 30726979584,166497435648,902168182784, 4888469241856,26488322654208,143528684683264, 777716068515840] |