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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 115 |
| 5 | 1051 |
| 6 | 11676 |
| 7 | 152839 |
| 8 | 2304261 |
| 9 | 39325276 |
| 10 | 749484505 |
| 11 | 15778499881 |
| 12 | 363654981768 |
| 13 | 9107153044081 |
| 14 | 246256787171955 |
| 15 | 7150553981030776 |
| 16 | 221913430199126011 |
| 17 | 7330293750552189139 |
| 18 | 256782194699525745876 |
| 19 | 9508271497633004786551 |
| 20 | 371079370602386712421365 |
[1,3,16,115,1051,11676,152839,2304261,39325276, 749484505,15778499881,363654981768,9107153044081, 246256787171955,7150553981030776, 221913430199126011,7330293750552189139, 256782194699525745876,9508271497633004786551, 371079370602386712421365] |