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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 44 |
| 3 | 192 |
| 4 | 726 |
| 5 | 2457 |
| 6 | 7648 |
| 7 | 22220 |
| 8 | 60993 |
| 9 | 159478 |
| 10 | 399906 |
| 11 | 966600 |
| 12 | 2261630 |
| 13 | 5139897 |
| 14 | 11378988 |
| 15 | 24598683 |
| 16 | 52033372 |
| 17 | 107890610 |
| 18 | 219630050 |
| 19 | 439535138 |
| 20 | 865784403 |
| 21 | 1680352500 |
| 22 | 3216454360 |
| 23 | 6077280123 |
| 24 | 11343018559 |
| 25 | 20928404349 |
| 26 | 38194869384 |
| 27 | 68989715838 |
[1,8,44,192,726,2457,7648,22220,60993,159478, 399906,966600,2261630,5139897,11378988,24598683, 52033372,107890610,219630050,439535138,865784403, 1680352500,3216454360,6077280123,11343018559, 20928404349,38194869384,68989715838] |