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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 12 |
| 2 | 310 |
| 3 | 15960 |
| 4 | 1275178 |
| 5 | 144435940 |
| 6 | 22125155806 |
| 7 | 4434275544496 |
| 8 | 1132379391991122 |
| 9 | 360443126615627452 |
| 10 | 140377052282997200262 |
| 11 | 65840588544634920144392 |
| 12 | 36684663022679611837425786 |
[2,12,310,15960,1275178,144435940,22125155806, 4434275544496,1132379391991122,360443126615627452, 140377052282997200262,65840588544634920144392, 36684663022679611837425786] |