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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 26 |
| 4 | 96 |
| 5 | 342 |
| 6 | 1266 |
| 7 | 4678 |
| 8 | 17548 |
| 9 | 66098 |
| 10 | 250854 |
| 11 | 956034 |
| 12 | 3660190 |
| 13 | 14059866 |
| 14 | 54176466 |
| 15 | 209290554 |
| 16 | 810370944 |
| 17 | 3143964294 |
| 18 | 12219099594 |
| 19 | 47564314774 |
| 20 | 185410843594 |
| 21 | 723668533278 |
| 22 | 2827767496998 |
| 23 | 11061197519166 |
[1,2,8,26,96,342,1266,4678,17548,66098,250854, 956034,3660190,14059866,54176466,209290554, 810370944,3143964294,12219099594,47564314774, 185410843594,723668533278,2827767496998, 11061197519166] |