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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 12 |
| 7 | 34 |
| 8 | 218 |
| 9 | 4278 |
| 10 | 431165 |
| 11 | 162267174 |
| 12 | 201636689352 |
| 13 | 777816803938932 |
| 14 | 9865957936943859185 |
| 15 | 395886667549681686369527 |
| 16 | 53716176608076643470380213991 |
| 17 | 23524515269630339982914608683548933 |
| 18 | 35682168849414944013547274439525153167248 |
[1,1,1,2,3,5,12,34,218,4278,431165,162267174, 201636689352,777816803938932,9865957936943859185, 395886667549681686369527, 53716176608076643470380213991, 23524515269630339982914608683548933, 35682168849414944013547274439525153167248] |