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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 21 |
| 3 | 661 |
| 4 | 28941 |
| 5 | 1678501 |
| 6 | 124467021 |
| 7 | 11484880261 |
| 8 | 1290503997741 |
| 9 | 173495416001701 |
| 10 | 27499205820027021 |
| 11 | 5075028072491665861 |
| 12 | 1078923766195953890541 |
| 13 | 261780612944688782844901 |
| 14 | 71901410584558939807059021 |
| 15 | 22195276604290979611365107461 |
| 16 | 7651037112318147566092161607341 |
[1,21,661,28941,1678501,124467021,11484880261, 1290503997741,173495416001701,27499205820027021, 5075028072491665861,1078923766195953890541, 261780612944688782844901, 71901410584558939807059021, 22195276604290979611365107461, 7651037112318147566092161607341] |