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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 15 |
| 4 | 630 |
| 5 | 2835 |
| 6 | 155925 |
| 7 | 6081075 |
| 8 | 1277025750 |
| 9 | 10854718875 |
| 10 | 1856156927625 |
| 11 | 194896477400625 |
| 12 | 2900518163668125 |
| 13 | 3698160658676859375 |
| 14 | 1298054391195577640625 |
| 15 | 263505041412702261046875 |
| 16 | 245059688513813102773593750 |
| 17 | 4043484860477916195764296875 |
[1,2,6,15,630,2835,155925,6081075,1277025750, 10854718875,1856156927625,194896477400625, 2900518163668125,3698160658676859375, 1298054391195577640625,263505041412702261046875, 245059688513813102773593750, 4043484860477916195764296875] |