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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 40 |
| 3 | 196 |
| 4 | 824 |
| 5 | 3404 |
| 6 | 13904 |
| 7 | 55452 |
| 8 | 224272 |
| 9 | 898392 |
| 10 | 3595276 |
| 11 | 14388352 |
| 12 | 57600180 |
| 13 | 230422684 |
| 14 | 921794036 |
| 15 | 3687382020 |
[1,8,40,196,824,3404,13904,55452,224272,898392, 3595276,14388352,57600180,230422684,921794036, 3687382020] |