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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 22 |
| 3 | 148 |
| 4 | 1126 |
| 5 | 6780 |
| 6 | 49020 |
| 7 | 290664 |
| 8 | 1945734 |
| 9 | 11786988 |
| 10 | 74564884 |
| 11 | 445398168 |
| 12 | 2767974620 |
| 13 | 16299877464 |
| 14 | 98372647992 |
| 15 | 577710929872 |
| 16 | 3417417696966 |
| 17 | 19822614160204 |
| 18 | 115774907274660 |
| 19 | 664999142005688 |
| 20 | 3833211645341172 |
| 21 | 21844173121980168 |
| 22 | 124494179613063496 |
| 23 | 703535711892561840 |
| 24 | 3974352552423163548 |
[1,2,22,148,1126,6780,49020,290664,1945734, 11786988,74564884,445398168,2767974620, 16299877464,98372647992,577710929872, 3417417696966,19822614160204,115774907274660, 664999142005688,3833211645341172, 21844173121980168,124494179613063496, 703535711892561840,3974352552423163548] |