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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 23 |
| 4 | 94 |
| 5 | 403 |
| 6 | 1762 |
| 7 | 7864 |
| 8 | 35690 |
| 9 | 164108 |
| 10 | 762357 |
| 11 | 3569242 |
| 12 | 16819681 |
| 13 | 79692636 |
| 14 | 379354005 |
| 15 | 1812988443 |
| 16 | 8694229731 |
| 17 | 41817451066 |
| 18 | 201659232415 |
| 19 | 974725502503 |
| 20 | 4721045311481 |
| 21 | 22908166197986 |
| 22 | 111341527565114 |
| 23 | 541962528735588 |
| 24 | 2641596154242981 |
| 25 | 12891279928029972 |
| 26 | 62981324355512110 |
| 27 | 308015721936263522 |
[1,2,6,23,94,403,1762,7864,35690,164108,762357, 3569242,16819681,79692636,379354005,1812988443, 8694229731,41817451066,201659232415,974725502503, 4721045311481,22908166197986,111341527565114, 541962528735588,2641596154242981, 12891279928029972,62981324355512110, 308015721936263522] |