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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 232 |
| 4 | 7952 |
| 5 | 405152 |
| 6 | 31111872 |
| 7 | 3115956352 |
| 8 | 414147567872 |
| 9 | 68413355397632 |
| 10 | 13936708915940352 |
| 11 | 3412444856961083392 |
| 12 | 987956358173680013312 |
| 13 | 334650367409781717573632 |
| 14 | 130572314003924554412900352 |
| 15 | 58337032599905770133366013952 |
[1,2,12,232,7952,405152,31111872,3115956352, 414147567872,68413355397632,13936708915940352, 3412444856961083392,987956358173680013312, 334650367409781717573632, 130572314003924554412900352, 58337032599905770133366013952] |