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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 13 |
| 5 | 36 |
| 6 | 128 |
| 7 | 422 |
| 8 | 1639 |
| 9 | 5949 |
| 10 | 24113 |
| 11 | 93309 |
| 12 | 391828 |
| 13 | 1583365 |
| 14 | 6804543 |
| 15 | 28395349 |
| 16 | 124390258 |
| 17 | 531687409 |
| 18 | 2362484441 |
| 19 | 10291265724 |
| 20 | 46279573814 |
| 21 | 204646979728 |
| 22 | 929108004632 |
| 23 | 4159489988998 |
| 24 | 19039705452731 |
| 25 | 86108778313062 |
| 26 | 396846467067471 |
| 27 | 1810271300484767 |
| 28 | 8392688367577943 |
[1,1,2,4,13,36,128,422,1639,5949,24113,93309, 391828,1583365,6804543,28395349,124390258, 531687409,2362484441,10291265724,46279573814, 204646979728,929108004632,4159489988998, 19039705452731,86108778313062,396846467067471, 1810271300484767,8392688367577943] |