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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 75 |
| 5 | 650 |
| 6 | 7238 |
| 7 | 98728 |
| 8 | 1597689 |
| 9 | 29965770 |
| 10 | 639867250 |
| 11 | 15337926824 |
| 12 | 408041226684 |
| 13 | 11934806334412 |
| 14 | 380779156844728 |
| 15 | 13163263492873152 |
| 16 | 490208180677163141 |
| 17 | 19568027053121979366 |
| 18 | 833594881998712829460 |
[1,3,12,75,650,7238,98728,1597689,29965770, 639867250,15337926824,408041226684,11934806334412, 380779156844728,13163263492873152, 490208180677163141,19568027053121979366, 833594881998712829460] |