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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 30 |
| 5 | 97 |
| 6 | 380 |
| 7 | 1432 |
| 8 | 5730 |
| 9 | 23215 |
| 10 | 95928 |
| 11 | 402954 |
| 12 | 1715098 |
| 13 | 7372699 |
| 14 | 32074694 |
| 15 | 140435319 |
| 16 | 620668756 |
| 17 | 2758615766 |
| 18 | 12342172004 |
| 19 | 55515576430 |
| 20 | 250924509615 |
| 21 | 1139470870886 |
| 22 | 5195091511618 |
| 23 | 23776892239251 |
| 24 | 109201412722348 |
| 25 | 503132997084698 |
| 26 | 2325166974024119 |
| 27 | 10774845621104857 |
| 28 | 50061102370626852 |
[1,1,3,8,30,97,380,1432,5730,23215,95928,402954, 1715098,7372699,32074694,140435319,620668756, 2758615766,12342172004,55515576430,250924509615, 1139470870886,5195091511618,23776892239251, 109201412722348,503132997084698,2325166974024119, 10774845621104857,50061102370626852] |