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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 52 |
| 4 | 646 |
| 5 | 13756 |
| 6 | 458780 |
| 7 | 24525352 |
| 8 | 2094232006 |
| 9 | 287618113900 |
| 10 | 63647556127412 |
| 11 | 22739228686869592 |
| 12 | 13126310109506278556 |
| 13 | 12250085882856201785816 |
| 14 | 18488349380363585366790264 |
| 15 | 45134497176992058331312333648 |
| 16 | 178246891228174428563552421395782 |
[1,2,6,52,646,13756,458780,24525352,2094232006, 287618113900,63647556127412,22739228686869592, 13126310109506278556,12250085882856201785816, 18488349380363585366790264, 45134497176992058331312333648, 178246891228174428563552421395782] |