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| n | a(n) |
|---|---|
| 1 | 21 |
| 2 | 373 |
| 3 | 8697 |
| 4 | 170148 |
| 5 | 3488015 |
| 6 | 70915451 |
| 7 | 1444700004 |
| 8 | 29426750811 |
| 9 | 599056249102 |
| 10 | 12196183065261 |
| 11 | 248303130737344 |
| 12 | 5055219016095223 |
| 13 | 102918285280874701 |
| 14 | 2095289674633493599 |
| 15 | 42657543159685926011 |
| 16 | 868455498699347842027 |
[21,373,8697,170148,3488015,70915451,1444700004, 29426750811,599056249102,12196183065261, 248303130737344,5055219016095223, 102918285280874701,2095289674633493599, 42657543159685926011,868455498699347842027] |