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| n | a(n) |
|---|---|
| 1 | 13 |
| 2 | 43 |
| 3 | 163 |
| 4 | 693 |
| 5 | 3223 |
| 6 | 16060 |
| 7 | 84207 |
| 8 | 457676 |
| 9 | 2549156 |
| 10 | 14430921 |
| 11 | 82566935 |
| 12 | 475670431 |
| 13 | 2752521185 |
| 14 | 15973183106 |
| 15 | 92863593361 |
| 16 | 540515596648 |
| 17 | 3148453277799 |
| 18 | 18348289100476 |
| 19 | 106961673453125 |
| 20 | 623658710038884 |
| 21 | 3636814272452146 |
[13,43,163,693,3223,16060,84207,457676,2549156, 14430921,82566935,475670431,2752521185, 15973183106,92863593361,540515596648, 3148453277799,18348289100476,106961673453125, 623658710038884,3636814272452146] |