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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 77 |
| 7 | 231 |
| 8 | 731 |
| 9 | 2363 |
| 10 | 7920 |
| 11 | 27084 |
| 12 | 94817 |
| 13 | 336983 |
| 14 | 1216568 |
| 15 | 4453388 |
| 16 | 16502271 |
| 17 | 61814816 |
| 18 | 233856348 |
| 19 | 892573723 |
| 20 | 3434288432 |
| 21 | 13314937000 |
| 22 | 51972107496 |
| 23 | 204140373934 |
| 24 | 806591451331 |
| 25 | 3204158551284 |
| 26 | 12792440649653 |
| 27 | 51316797101243 |
| 28 | 206757825981157 |
| 29 | 836465018168185 |
| 30 | 3397296971539772 |
[1,1,2,4,10,26,77,231,731,2363,7920,27084,94817, 336983,1216568,4453388,16502271,61814816, 233856348,892573723,3434288432,13314937000, 51972107496,204140373934,806591451331, 3204158551284,12792440649653,51316797101243, 206757825981157,836465018168185,3397296971539772] |