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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 36 |
| 3 | 376 |
| 4 | 3936 |
| 5 | 41216 |
| 6 | 431616 |
| 7 | 4519936 |
| 8 | 47333376 |
| 9 | 495681536 |
| 10 | 5190844416 |
| 11 | 54359228416 |
| 12 | 569257230336 |
| 13 | 5961339109376 |
| 14 | 62427953627136 |
| 15 | 653754017775616 |
| 16 | 6846200955273216 |
| 17 | 71694347178868736 |
| 18 | 750792950862053376 |
[4,36,376,3936,41216,431616,4519936,47333376, 495681536,5190844416,54359228416,569257230336, 5961339109376,62427953627136,653754017775616, 6846200955273216,71694347178868736, 750792950862053376] |