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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 13 |
| 4 | 59 |
| 5 | 193 |
| 6 | 895 |
| 7 | 3259 |
| 8 | 15291 |
| 9 | 58641 |
| 10 | 278023 |
| 11 | 1107235 |
| 12 | 5295601 |
| 13 | 21602507 |
| 14 | 103888769 |
| 15 | 431979255 |
| 16 | 2088322907 |
| 17 | 8809419485 |
| 18 | 42735313349 |
| 19 | 182391672799 |
| 20 | 887657036207 |
| 21 | 3825232735637 |
| 22 | 18661736385173 |
| 23 | 81064401244013 |
| 24 | 396325426798887 |
| 25 | 1733517914129193 |
| 26 | 8490333231128203 |
| 27 | 37355022085126659 |
[1,1,5,13,59,193,895,3259,15291,58641,278023, 1107235,5295601,21602507,103888769,431979255, 2088322907,8809419485,42735313349,182391672799, 887657036207,3825232735637,18661736385173, 81064401244013,396325426798887,1733517914129193, 8490333231128203,37355022085126659] |