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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 42 |
| 5 | 150 |
| 6 | 36270 |
| 7 | 270900 |
| 8 | 9440379900 |
| 9 | 3332912051700 |
| 10 | 2004302168707167000 |
| 11 | 1424191116445997823000 |
| 12 | 3936008766237071969447818200 |
| 13 | 10888542544398564939894000 |
| 14 | 3606055788316324023953497288103040 |
[1,1,3,42,150,36270,270900,9440379900, 3332912051700,2004302168707167000, 1424191116445997823000, 3936008766237071969447818200, 10888542544398564939894000, 3606055788316324023953497288103040] |