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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 43 |
| 5 | 139 |
| 6 | 466 |
| 7 | 1603 |
| 8 | 5627 |
| 9 | 20070 |
| 10 | 72521 |
| 11 | 264861 |
| 12 | 975996 |
| 13 | 3623680 |
| 14 | 13540852 |
| 15 | 50880391 |
| 16 | 192109376 |
| 17 | 728417406 |
| 18 | 2772227203 |
| 19 | 10585500249 |
| 20 | 40538986928 |
| 21 | 155661286100 |
| 22 | 599128863537 |
| 23 | 2310961487189 |
| 24 | 8931238199580 |
| 25 | 34578129966890 |
| 26 | 134089763743373 |
| 27 | 520757083293026 |
| 28 | 2025200075312320 |
[1,2,5,14,43,139,466,1603,5627,20070,72521,264861, 975996,3623680,13540852,50880391,192109376, 728417406,2772227203,10585500249,40538986928, 155661286100,599128863537,2310961487189, 8931238199580,34578129966890,134089763743373, 520757083293026,2025200075312320] |