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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 33 |
| 5 | 169 |
| 6 | 1019 |
| 7 | 7136 |
| 8 | 57092 |
| 9 | 513832 |
| 10 | 5138329 |
| 11 | 56521628 |
| 12 | 678259545 |
| 13 | 8817374087 |
| 14 | 123443237218 |
| 15 | 1851648558279 |
| 16 | 29626376932478 |
| 17 | 503648407852135 |
| 18 | 9065671341338443 |
| 19 | 172247755485430423 |
| 20 | 3444955109708608469 |
[1,2,8,33,169,1019,7136,57092,513832,5138329, 56521628,678259545,8817374087,123443237218, 1851648558279,29626376932478,503648407852135, 9065671341338443,172247755485430423, 3444955109708608469] |