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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 9 |
| 3 | 51 |
| 4 | 1275 |
| 5 | 8415 |
| 6 | 115005 |
| 7 | 805035 |
| 8 | 45886995 |
| 9 | 331406075 |
| 10 | 4838528695 |
| 11 | 35629165845 |
| 12 | 1056998586735 |
| 13 | 7886835608715 |
| 14 | 118302534130725 |
| 15 | 891212423784795 |
| 16 | 107836703277960195 |
| 17 | 818290277815109715 |
[1,1,9,51,1275,8415,115005,805035,45886995, 331406075,4838528695,35629165845,1056998586735, 7886835608715,118302534130725,891212423784795, 107836703277960195,818290277815109715] |