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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 26 |
| 4 | 150 |
| 5 | 1114 |
| 6 | 10614 |
| 7 | 131002 |
| 8 | 2128278 |
| 9 | 46294426 |
| 10 | 1368718518 |
| 11 | 55647242106 |
| 12 | 3137452915158 |
| 13 | 246751601425242 |
| 14 | 27181289502625014 |
| 15 | 4205716133932054842 |
| 16 | 915890632125187606038 |
| 17 | 281117681559174501597466 |
| 18 | 121733516122198763782243638 |
[1,2,6,26,150,1114,10614,131002,2128278,46294426, 1368718518,55647242106,3137452915158, 246751601425242,27181289502625014, 4205716133932054842,915890632125187606038, 281117681559174501597466, 121733516122198763782243638] |