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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 8 |
| 5 | 44 |
| 6 | 411 |
| 7 | 4682 |
| 8 | 66524 |
| 9 | 1111134 |
| 10 | 21437357 |
| 11 | 469070942 |
| 12 | 11488238992 |
| 13 | 311505013052 |
| 14 | 9267596377239 |
| 15 | 300239975166840 |
| 16 | 10523614185609344 |
| 17 | 396861212733968144 |
| 18 | 16024522976922760209 |
| 19 | 689852631578947368422 |
[1,1,2,8,44,411,4682,66524,1111134,21437357, 469070942,11488238992,311505013052,9267596377239, 300239975166840,10523614185609344, 396861212733968144,16024522976922760209, 689852631578947368422] |