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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 286 |
| 5 | 144305 |
| 6 | 276620298878 |
| 7 | 4929053594885296570083 |
| 8 | 2778177345800469611391891486368048702791639566906088871615186 |
[1,1,2,7,286,144305,276620298878, 4929053594885296570083, 27781773458004696113918914863680487027916395669060\ 88871615186] |