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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 103 |
| 4 | 833 |
| 5 | 7381 |
| 6 | 69276 |
| 7 | 676555 |
| 8 | 6802814 |
| 9 | 69949499 |
| 10 | 732099536 |
| 11 | 7773188813 |
| 12 | 83521931171 |
| 13 | 906478836870 |
| 14 | 9922793839711 |
| 15 | 109426668183175 |
| 16 | 1214551788118680 |
| 17 | 13557416935589156 |
| 18 | 152099318341418174 |
| 19 | 1714087810020632151 |
| 20 | 19395280422854560090 |
| 21 | 220265616659410691342 |
[1,3,15,103,833,7381,69276,676555,6802814, 69949499,732099536,7773188813,83521931171, 906478836870,9922793839711,109426668183175, 1214551788118680,13557416935589156, 152099318341418174,1714087810020632151, 19395280422854560090,220265616659410691342] |