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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 146 |
| 5 | 748 |
| 6 | 4002 |
| 7 | 22114 |
| 8 | 125220 |
| 9 | 722850 |
| 10 | 4238148 |
| 11 | 25169064 |
| 12 | 151084168 |
| 13 | 915235106 |
| 14 | 5587985801 |
| 15 | 34351213384 |
| 16 | 212436911849 |
| 17 | 1320744403708 |
| 18 | 8250065775120 |
| 19 | 51752790871466 |
| 20 | 325887027304769 |
| 21 | 2059216160242430 |
| 22 | 13052805881695018 |
| 23 | 82976612756731258 |
[1,2,8,30,146,748,4002,22114,125220,722850, 4238148,25169064,151084168,915235106,5587985801, 34351213384,212436911849,1320744403708, 8250065775120,51752790871466,325887027304769, 2059216160242430,13052805881695018, 82976612756731258] |