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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 19 |
| 5 | 61 |
| 6 | 199 |
| 7 | 661 |
| 8 | 2234 |
| 9 | 7668 |
| 10 | 26674 |
| 11 | 93858 |
| 12 | 333524 |
| 13 | 1195288 |
| 14 | 4315468 |
| 15 | 15681838 |
| 16 | 57312643 |
| 17 | 210529213 |
| 18 | 776872243 |
| 19 | 2878482523 |
| 20 | 10704933793 |
| 21 | 39945106573 |
| 22 | 149511432793 |
| 23 | 561182969173 |
| 24 | 2111812422871 |
| 25 | 7965992783803 |
| 26 | 30114859723751 |
| 27 | 114079902339303 |
| 28 | 432975153092011 |
| 29 | 1646215731143667 |
[0,1,2,6,19,61,199,661,2234,7668,26674,93858, 333524,1195288,4315468,15681838,57312643, 210529213,776872243,2878482523,10704933793, 39945106573,149511432793,561182969173, 2111812422871,7965992783803,30114859723751, 114079902339303,432975153092011,1646215731143667] |