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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 49 |
| 5 | 241 |
| 6 | 721 |
| 7 | 6721 |
| 8 | 124321 |
| 9 | 913249 |
| 10 | 4243681 |
| 11 | 94818241 |
| 12 | 1640604241 |
| 13 | 14642181841 |
| 14 | 131026944049 |
| 15 | 3669304504321 |
| 16 | 62536989802561 |
| 17 | 627395160826561 |
| 18 | 10818406189690561 |
| 19 | 308036857749752449 |
| 20 | 5219006583104930161 |
| 21 | 65146235714284117681 |
[1,1,1,1,49,241,721,6721,124321,913249,4243681, 94818241,1640604241,14642181841,131026944049, 3669304504321,62536989802561,627395160826561, 10818406189690561,308036857749752449, 5219006583104930161,65146235714284117681] |