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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 33 |
| 5 | 186 |
| 6 | 1213 |
| 7 | 8949 |
| 8 | 73300 |
| 9 | 657589 |
| 10 | 6396829 |
| 11 | 66936872 |
| 12 | 748528619 |
| 13 | 8896663389 |
| 14 | 111873459298 |
| 15 | 1482522176651 |
| 16 | 20633389026901 |
| 17 | 300705290677218 |
| 18 | 4576892504775417 |
| 19 | 72584518271451169 |
| 20 | 1196883163316172252 |
| 21 | 20482129284796798609 |
| 22 | 363138667441109774065 |
| 23 | 6659922487212111452776 |
[1,1,2,7,33,186,1213,8949,73300,657589,6396829, 66936872,748528619,8896663389,111873459298, 1482522176651,20633389026901,300705290677218, 4576892504775417,72584518271451169, 1196883163316172252,20482129284796798609, 363138667441109774065,6659922487212111452776] |