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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 51 |
| 5 | 255 |
| 6 | 1845 |
| 7 | 12915 |
| 8 | 129465 |
| 9 | 1165185 |
| 10 | 13338675 |
| 11 | 146725425 |
| 12 | 2023126875 |
| 13 | 26300649375 |
| 14 | 405966485925 |
| 15 | 6089497288875 |
| 16 | 110674075136625 |
| 17 | 1881459277322625 |
| 18 | 36921598987147875 |
| 19 | 701510380755809625 |
| 20 | 15370603498046671875 |
| 21 | 322782673458980109375 |
| 22 | 7608990209632029343125 |
| 23 | 175006774821536674891875 |
[1,1,3,9,51,255,1845,12915,129465,1165185, 13338675,146725425,2023126875,26300649375, 405966485925,6089497288875,110674075136625, 1881459277322625,36921598987147875, 701510380755809625,15370603498046671875, 322782673458980109375,7608990209632029343125, 175006774821536674891875] |