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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 25 |
| 4 | 100 |
| 5 | 388 |
| 6 | 1632 |
| 7 | 6786 |
| 8 | 29287 |
| 9 | 125113 |
| 10 | 550128 |
| 11 | 2406584 |
| 12 | 10712694 |
| 13 | 47474007 |
| 14 | 213394404 |
| 15 | 956947559 |
| 16 | 4332774635 |
| 17 | 19577754886 |
| 18 | 89181193579 |
| 19 | 405820090361 |
| 20 | 1857550386541 |
| 21 | 8495079111238 |
| 22 | 39046539443296 |
| 23 | 179406094099381 |
| 24 | 827476958191883 |
| 25 | 3815466697125080 |
| 26 | 17651866802706634 |
| 27 | 81662775275630439 |
[1,2,7,25,100,388,1632,6786,29287,125113,550128, 2406584,10712694,47474007,213394404,956947559, 4332774635,19577754886,89181193579,405820090361, 1857550386541,8495079111238,39046539443296, 179406094099381,827476958191883,3815466697125080, 17651866802706634,81662775275630439] |