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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 8 |
| 3 | 85 |
| 4 | 1128 |
| 5 | 16451 |
| 6 | 255704 |
| 7 | 4141383 |
| 8 | 69159400 |
| 9 | 1182125128 |
| 10 | 20581159608 |
| 11 | 363704640476 |
| 12 | 6506965279992 |
| 13 | 117626432708864 |
| 14 | 2145180358634664 |
| 15 | 39421026305282660 |
| 16 | 729242353169440744 |
| 17 | 13568988503585900648 |
| 18 | 253785064586356459616 |
| 19 | 4768543107831461199897 |
[1,1,8,85,1128,16451,255704,4141383,69159400, 1182125128,20581159608,363704640476,6506965279992, 117626432708864,2145180358634664, 39421026305282660,729242353169440744, 13568988503585900648,253785064586356459616, 4768543107831461199897] |