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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 4 |
| 3 | 350 |
| 4 | 7208 |
| 5 | 1520218 |
| 6 | 106485740 |
| 7 | 38051376246 |
| 8 | 6123846322896 |
| 9 | 3217389043510578 |
| 10 | 964215477538459732 |
| 11 | 692917532440212444686 |
| 12 | 338776184246581290006520 |
| 13 | 318786053587029917056642186 |
[0,2,4,350,7208,1520218,106485740,38051376246, 6123846322896,3217389043510578,964215477538459732, 692917532440212444686,338776184246581290006520, 318786053587029917056642186] |