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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 114 |
| 6 | 438 |
| 7 | 1739 |
| 8 | 7077 |
| 9 | 29364 |
| 10 | 123756 |
| 11 | 528324 |
| 12 | 2279868 |
| 13 | 9928679 |
| 14 | 43580301 |
| 15 | 192601419 |
| 16 | 856317717 |
| 17 | 3827501985 |
| 18 | 17188943523 |
| 19 | 77521747638 |
| 20 | 350959738842 |
| 21 | 1594390493067 |
| 22 | 7266093316649 |
| 23 | 33209221327752 |
| 24 | 152182572790008 |
| 25 | 699083290518817 |
| 26 | 3218624408121555 |
[1,1,3,9,31,114,438,1739,7077,29364,123756,528324, 2279868,9928679,43580301,192601419,856317717, 3827501985,17188943523,77521747638,350959738842, 1594390493067,7266093316649,33209221327752, 152182572790008,699083290518817,3218624408121555] |