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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 8 |
| 5 | 27 |
| 6 | 79 |
| 7 | 270 |
| 8 | 894 |
| 9 | 3130 |
| 10 | 11011 |
| 11 | 39622 |
| 12 | 143879 |
| 13 | 528919 |
| 14 | 1960248 |
| 15 | 7323999 |
| 16 | 27542451 |
| 17 | 104194485 |
| 18 | 396204388 |
| 19 | 1513599583 |
| 20 | 5806283770 |
| 21 | 22356914550 |
| 22 | 86376741339 |
| 23 | 334752355281 |
| 24 | 1300999638753 |
| 25 | 5069411676111 |
| 26 | 19800500391264 |
[1,1,1,4,8,27,79,270,894,3130,11011,39622,143879, 528919,1960248,7323999,27542451,104194485, 396204388,1513599583,5806283770,22356914550, 86376741339,334752355281,1300999638753, 5069411676111,19800500391264] |