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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 30 |
| 5 | 104 |
| 6 | 379 |
| 7 | 1437 |
| 8 | 5497 |
| 9 | 21237 |
| 10 | 84414 |
| 11 | 337434 |
| 12 | 1350955 |
| 13 | 5488288 |
| 14 | 22477310 |
| 15 | 92056160 |
| 16 | 379557876 |
| 17 | 1576415883 |
| 18 | 6555545218 |
| 19 | 27337486848 |
| 20 | 114605627815 |
| 21 | 481547395405 |
| 22 | 2026228030548 |
| 23 | 8554574318460 |
| 24 | 36207535787135 |
| 25 | 153429772295518 |
| 26 | 651502398352393 |
| 27 | 2772592303600016 |
| 28 | 11813838712985613 |
[1,1,3,9,30,104,379,1437,5497,21237,84414,337434, 1350955,5488288,22477310,92056160,379557876, 1576415883,6555545218,27337486848,114605627815, 481547395405,2026228030548,8554574318460, 36207535787135,153429772295518,651502398352393, 2772592303600016,11813838712985613] |