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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 67 |
| 4 | 717 |
| 5 | 10141 |
| 6 | 179353 |
| 7 | 3816989 |
| 8 | 95076537 |
| 9 | 2714895433 |
| 10 | 87457961421 |
| 11 | 3138260371225 |
| 12 | 124147801973605 |
| 13 | 5368353187693757 |
| 14 | 251928853285058433 |
| 15 | 12752446755011776741 |
| 16 | 692625349011401620209 |
| 17 | 40178978855796929378065 |
| 18 | 2479383850197948228950293 |
[1,2,9,67,717,10141,179353,3816989,95076537, 2714895433,87457961421,3138260371225, 124147801973605,5368353187693757, 251928853285058433,12752446755011776741, 692625349011401620209,40178978855796929378065, 2479383850197948228950293] |