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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 60 |
| 3 | 422 |
| 4 | 2784 |
| 5 | 17318 |
| 6 | 102600 |
| 7 | 584942 |
| 8 | 3237504 |
| 9 | 17516438 |
| 10 | 93136440 |
| 11 | 488625662 |
| 12 | 2537103024 |
| 13 | 13068059558 |
| 14 | 66890498280 |
| 15 | 340713533582 |
| 16 | 1728792901344 |
| 17 | 8745409322678 |
| 18 | 44134458900120 |
| 19 | 222306845468702 |
| 20 | 1118087142184464 |
| 21 | 5616691514201798 |
| 22 | 28188613237893960 |
[8,60,422,2784,17318,102600,584942,3237504, 17516438,93136440,488625662,2537103024, 13068059558,66890498280,340713533582, 1728792901344,8745409322678,44134458900120, 222306845468702,1118087142184464,5616691514201798, 28188613237893960] |