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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 53 |
| 4 | 258 |
| 5 | 25746 |
| 6 | 53746 |
| 7 | 161946 |
| 8 | 7930238 |
| 9 | 14927378 |
| 10 | 29810546 |
| 11 | 4714751561 |
| 12 | 25742623453 |
| 13 | 94268917816334704578 |
[1,2,53,258,25746,53746,161946,7930238,14927378, 29810546,4714751561,25742623453, 94268917816334704578] |