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| n | a(n) |
|---|---|
| 10 | 1 |
| 11 | 20 |
| 12 | 349 |
| 13 | 5954 |
| 14 | 103194 |
| 15 | 1845480 |
| 16 | 34288800 |
| 17 | 663848640 |
| 18 | 13406178240 |
| 19 | 282398538240 |
| 20 | 6201593613645 |
| 21 | 141859542537845 |
| 22 | 3376683552323421 |
| 23 | 83546513273754977 |
| 24 | 2146303277645066980 |
| 25 | 57187254952684274700 |
| 26 | 1578640101972070456800 |
| 27 | 45101111852055549981600 |
[1,20,349,5954,103194,1845480,34288800,663848640, 13406178240,282398538240,6201593613645, 141859542537845,3376683552323421, 83546513273754977,2146303277645066980, 57187254952684274700,1578640101972070456800, 45101111852055549981600] |