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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 15 |
| 5 | 66 |
| 6 | 357 |
| 7 | 1891 |
| 8 | 20559 |
| 9 | 257605 |
| 10 | 3436908 |
| 11 | 96199478 |
| 12 | 2734569969 |
| 13 | 96260508267 |
| 14 | 6820892444439 |
| 15 | 438665726703387 |
| 16 | 43006289605790127 |
| 17 | 7366025744010911808 |
| 18 | 1099005822684238964181 |
| 19 | 309398207716948885643749 |
[1,3,7,15,66,357,1891,20559,257605,3436908, 96199478,2734569969,96260508267,6820892444439, 438665726703387,43006289605790127, 7366025744010911808,1099005822684238964181, 309398207716948885643749] |