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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 70 |
| 4 | 485 |
| 5 | 3586 |
| 6 | 27702 |
| 7 | 221044 |
| 8 | 1807751 |
| 9 | 15073208 |
| 10 | 127658948 |
| 11 | 1095160206 |
| 12 | 9496825919 |
| 13 | 83109648780 |
| 14 | 733063257227 |
| 15 | 6510317010502 |
| 16 | 58166005554886 |
| 17 | 522446273512866 |
| 18 | 4714846241261093 |
| 19 | 42730135199777198 |
| 20 | 388741207648594732 |
| 21 | 3548875263271057666 |
| 22 | 32500492203726887011 |
[1,2,11,70,485,3586,27702,221044,1807751,15073208, 127658948,1095160206,9496825919,83109648780, 733063257227,6510317010502,58166005554886, 522446273512866,4714846241261093, 42730135199777198,388741207648594732, 3548875263271057666,32500492203726887011] |