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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 23 |
| 4 | 95 |
| 5 | 404 |
| 6 | 1772 |
| 7 | 7929 |
| 8 | 36069 |
| 9 | 166206 |
| 10 | 773209 |
| 11 | 3624790 |
| 12 | 17102065 |
| 13 | 81114678 |
| 14 | 386455320 |
| 15 | 1848256530 |
| 16 | 8868663304 |
| 17 | 42677840782 |
| 18 | 205893327059 |
| 19 | 995519646831 |
| 20 | 4823016017342 |
| 21 | 23407664566654 |
| 22 | 113786451683742 |
| 23 | 553923082837816 |
| 24 | 2700082575328009 |
| 25 | 13177194181392696 |
| 26 | 64378824026712682 |
| 27 | 314846186346791493 |
[1,2,6,23,95,404,1772,7929,36069,166206,773209, 3624790,17102065,81114678,386455320,1848256530, 8868663304,42677840782,205893327059,995519646831, 4823016017342,23407664566654,113786451683742, 553923082837816,2700082575328009, 13177194181392696,64378824026712682, 314846186346791493] |