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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 3 |
| 3 | 5 |
| 4 | 24 |
| 5 | 78 |
| 6 | 325 |
| 7 | 1272 |
| 8 | 5373 |
| 9 | 22572 |
| 10 | 97762 |
| 11 | 425716 |
| 12 | 1882062 |
| 13 | 8375064 |
| 14 | 37601643 |
| 15 | 169773435 |
| 16 | 771096972 |
| 17 | 3518065767 |
| 18 | 16119884297 |
| 19 | 74125225732 |
| 20 | 341970676466 |
| 21 | 1582133854847 |
| 22 | 7338641255894 |
| 23 | 34117910537671 |
| 24 | 158946919835352 |
| 25 | 741884929970516 |
| 26 | 3468677541274922 |
[1,0,3,5,24,78,325,1272,5373,22572,97762,425716, 1882062,8375064,37601643,169773435,771096972, 3518065767,16119884297,74125225732,341970676466, 1582133854847,7338641255894,34117910537671, 158946919835352,741884929970516,3468677541274922] |