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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 112 |
| 5 | 872 |
| 6 | 14372 |
| 7 | 154480 |
| 8 | 3098480 |
| 9 | 59710816 |
| 10 | 1688186176 |
| 11 | 27925409152 |
| 12 | 1327833590272 |
| 13 | 25675495200768 |
| 14 | 1017195720916224 |
| 15 | 47444016840290304 |
| 16 | 2267031138313024512 |
| 17 | 56480432945454004224 |
| 18 | 4051971981329937580032 |
[1,3,14,112,872,14372,154480,3098480,59710816, 1688186176,27925409152,1327833590272, 25675495200768,1017195720916224,47444016840290304, 2267031138313024512,56480432945454004224, 4051971981329937580032] |