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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 10 |
| 2 | 70 |
| 3 | 510 |
| 4 | 3720 |
| 5 | 27142 |
| 6 | 198034 |
| 7 | 1444904 |
| 8 | 10542368 |
| 9 | 76919662 |
| 10 | 561224422 |
| 11 | 4094828862 |
| 12 | 29876859864 |
| 13 | 217988781808 |
| 14 | 1590498774316 |
| 15 | 11604663002012 |
| 16 | 84670422615182 |
| 17 | 617775842744470 |
| 18 | 4507441679052256 |
| 19 | 32887382581680414 |
[1,10,70,510,3720,27142,198034,1444904,10542368, 76919662,561224422,4094828862,29876859864, 217988781808,1590498774316,11604663002012, 84670422615182,617775842744470,4507441679052256, 32887382581680414] |