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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 37 |
| 5 | 157 |
| 6 | 811 |
| 7 | 4309 |
| 8 | 26327 |
| 9 | 164947 |
| 10 | 1151477 |
| 11 | 8224863 |
| 12 | 64158567 |
| 13 | 511177515 |
| 14 | 4386520201 |
| 15 | 38389960685 |
| 16 | 358214414675 |
| 17 | 3404632390971 |
| 18 | 34234771676473 |
| 19 | 350261221644771 |
| 20 | 3768281045014927 |
| 21 | 41210302324325919 |
| 22 | 471585931164213345 |
| 23 | 5480984322433817771 |
| 24 | 66388136273738685321 |
[1,1,3,9,37,157,811,4309,26327,164947,1151477, 8224863,64158567,511177515,4386520201,38389960685, 358214414675,3404632390971,34234771676473, 350261221644771,3768281045014927, 41210302324325919,471585931164213345, 5480984322433817771,66388136273738685321] |