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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 17 |
| 4 | 80 |
| 5 | 371 |
| 6 | 1714 |
| 7 | 7904 |
| 8 | 36451 |
| 9 | 168098 |
| 10 | 775200 |
| 11 | 3574898 |
| 12 | 16485939 |
| 13 | 76026256 |
| 14 | 350601298 |
| 15 | 1616826563 |
| 16 | 7456127936 |
| 17 | 34384543809 |
| 18 | 158567136067 |
| 19 | 731245317072 |
| 20 | 3372197587729 |
| 21 | 15551164985523 |
| 22 | 71715469249777 |
| 23 | 330721752004000 |
[1,3,17,80,371,1714,7904,36451,168098,775200, 3574898,16485939,76026256,350601298,1616826563, 7456127936,34384543809,158567136067,731245317072, 3372197587729,15551164985523,71715469249777, 330721752004000] |