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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 55 |
| 5 | 196 |
| 6 | 2730 |
| 7 | 10032 |
| 8 | 108999 |
| 9 | 973258 |
| 10 | 20780331 |
| 11 | 79309308 |
| 12 | 2614200602 |
| 13 | 10073335754 |
| 14 | 288845706742 |
| 15 | 11805287917646 |
| 16 | 254331289285523 |
[1,3,10,55,196,2730,10032,108999,973258,20780331, 79309308,2614200602,10073335754,288845706742, 11805287917646,254331289285523] |