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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 15 |
| 3 | 206 |
| 4 | 4193 |
| 5 | 113904 |
| 6 | 3882511 |
| 7 | 159475280 |
| 8 | 7672503681 |
| 9 | 423360926720 |
| 10 | 26362968645071 |
| 11 | 1829066086810368 |
| 12 | 139929538526047585 |
| 13 | 11703312997355442176 |
| 14 | 1062423600515479191375 |
| 15 | 104042389901715413633024 |
| 16 | 10933256593926589800851969 |
| 17 | 1227201235266954603172331520 |
[1,2,15,206,4193,113904,3882511,159475280, 7672503681,423360926720,26362968645071, 1829066086810368,139929538526047585, 11703312997355442176,1062423600515479191375, 104042389901715413633024, 10933256593926589800851969, 1227201235266954603172331520] |