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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 40 |
| 3 | 213 |
| 4 | 1049 |
| 5 | 5034 |
| 6 | 23984 |
| 7 | 114069 |
| 8 | 542295 |
| 9 | 2577870 |
| 10 | 12253948 |
| 11 | 58249011 |
| 12 | 276885683 |
| 13 | 1316170990 |
| 14 | 6256394122 |
| 15 | 29739651711 |
| 16 | 141366874247 |
| 17 | 671984773580 |
| 18 | 3194266961582 |
| 19 | 15183887824311 |
| 20 | 72176324719925 |
| 21 | 343088799809408 |
| 22 | 1630866146364842 |
| 23 | 7752291502484181 |
[6,40,213,1049,5034,23984,114069,542295,2577870, 12253948,58249011,276885683,1316170990,6256394122, 29739651711,141366874247,671984773580, 3194266961582,15183887824311,72176324719925, 343088799809408,1630866146364842,7752291502484181] |