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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 54 |
| 3 | 631 |
| 4 | 7678 |
| 5 | 93398 |
| 6 | 1137850 |
| 7 | 13857444 |
| 8 | 168717375 |
| 9 | 2053766992 |
| 10 | 24997337148 |
| 11 | 304235229651 |
| 12 | 3702632940296 |
| 13 | 45061321786573 |
| 14 | 548394286665966 |
| 15 | 6673898631211550 |
| 16 | 81220384265578677 |
| 17 | 988438827804013263 |
[4,54,631,7678,93398,1137850,13857444,168717375, 2053766992,24997337148,304235229651,3702632940296, 45061321786573,548394286665966,6673898631211550, 81220384265578677,988438827804013263] |