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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 51 |
| 5 | 206 |
| 6 | 855 |
| 7 | 3585 |
| 8 | 15155 |
| 9 | 64525 |
| 10 | 276278 |
| 11 | 1188353 |
| 12 | 5130999 |
| 13 | 22226049 |
| 14 | 96544003 |
| 15 | 420368858 |
| 16 | 1834203955 |
| 17 | 8018057345 |
| 18 | 35107961175 |
| 19 | 153950675585 |
| 20 | 675978772326 |
| 21 | 2971700764941 |
| 22 | 13078268135683 |
| 23 | 57613905606273 |
| 24 | 254038914924791 |
| 25 | 1121081799217231 |
[1,1,3,13,51,206,855,3585,15155,64525,276278, 1188353,5130999,22226049,96544003,420368858, 1834203955,8018057345,35107961175,153950675585, 675978772326,2971700764941,13078268135683, 57613905606273,254038914924791,1121081799217231] |