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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 53 |
| 6 | 434 |
| 7 | 5695 |
| 8 | 120029 |
| 9 | 4086681 |
| 10 | 224887484 |
| 11 | 20019072757 |
| 12 | 2882971364492 |
| 13 | 671752346999393 |
| 14 | 253253517790135653 |
| 15 | 154485317604329747723 |
| 16 | 152477261728991251138254 |
| 17 | 243506341466516632397539361 |
| 18 | 629220538826740707106492847078 |
[0,1,1,3,10,53,434,5695,120029,4086681,224887484, 20019072757,2882971364492,671752346999393, 253253517790135653,154485317604329747723, 152477261728991251138254, 243506341466516632397539361, 629220538826740707106492847078] |