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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 21 |
| 3 | 231 |
| 4 | 385 |
| 5 | 7315 |
| 6 | 168245 |
| 7 | 4542615 |
| 8 | 140821065 |
| 9 | 28164213 |
| 10 | 366134769 |
| 11 | 15743795067 |
| 12 | 739958368149 |
| 13 | 12579292258533 |
| 14 | 62896461292665 |
| 15 | 3710891216267235 |
| 16 | 3710891216267235 |
| 17 | 248629711489904745 |
| 18 | 17652709515783236895 |
| 19 | 88263547578916184475 |
| 20 | 6972820258734378573525 |
[3,21,231,385,7315,168245,4542615,140821065, 28164213,366134769,15743795067,739958368149, 12579292258533,62896461292665,3710891216267235, 3710891216267235,248629711489904745, 17652709515783236895,88263547578916184475, 6972820258734378573525] |