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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 12 |
| 4 | 58 |
| 5 | 273 |
| 6 | 1329 |
| 7 | 6839 |
| 8 | 37423 |
| 9 | 217606 |
| 10 | 1340597 |
| 11 | 8719806 |
| 12 | 59680387 |
| 13 | 428481322 |
| 14 | 3218109788 |
| 15 | 25220647760 |
| 16 | 205790862332 |
| 17 | 1744755841379 |
| 18 | 15342274425585 |
| 19 | 139692065365753 |
| 20 | 1314995731359189 |
| 21 | 12780466391685166 |
| 22 | 128081591768679823 |
| 23 | 1322011886920066940 |
[2,12,58,273,1329,6839,37423,217606,1340597, 8719806,59680387,428481322,3218109788,25220647760, 205790862332,1744755841379,15342274425585, 139692065365753,1314995731359189, 12780466391685166,128081591768679823, 1322011886920066940] |