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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 9 |
| 3 | 29 |
| 4 | 109 |
| 5 | 531 |
| 6 | 2276 |
| 7 | 9485 |
| 8 | 41333 |
| 9 | 179345 |
| 10 | 769838 |
| 11 | 3318436 |
| 12 | 14331995 |
| 13 | 61806029 |
| 14 | 266512626 |
| 15 | 1149721593 |
| 16 | 4959529556 |
| 17 | 21392085393 |
| 18 | 92275053866 |
| 19 | 398035409724 |
| 20 | 1716936954230 |
| 21 | 7406064472068 |
| 22 | 31946418824054 |
| 23 | 137802367508923 |
[2,9,29,109,531,2276,9485,41333,179345,769838, 3318436,14331995,61806029,266512626,1149721593, 4959529556,21392085393,92275053866,398035409724, 1716936954230,7406064472068,31946418824054, 137802367508923] |