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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 48 |
| 3 | 392 |
| 4 | 4678 |
| 5 | 43676 |
| 6 | 406396 |
| 7 | 3568906 |
| 8 | 30554390 |
| 9 | 254834078 |
| 10 | 2085479610 |
| 11 | 16791859330 |
| 12 | 133416458104 |
| 13 | 1048095087616 |
| 14 | 8154539310958 |
| 15 | 62918331433308 |
| 16 | 481954854686434 |
| 17 | 3668399080453520 |
| 18 | 27766093432542984 |
| 19 | 209120844634276158 |
| 20 | 1568050593805721822 |
[1,48,392,4678,43676,406396,3568906,30554390, 254834078,2085479610,16791859330,133416458104, 1048095087616,8154539310958,62918331433308, 481954854686434,3668399080453520, 27766093432542984,209120844634276158, 1568050593805721822] |