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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 22 |
| 4 | 84 |
| 5 | 349 |
| 6 | 1489 |
| 7 | 6522 |
| 8 | 29167 |
| 9 | 131937 |
| 10 | 604928 |
| 11 | 2795191 |
| 12 | 13026035 |
| 13 | 61071104 |
| 14 | 287955729 |
| 15 | 1364135422 |
| 16 | 6488835986 |
| 17 | 30978176466 |
| 18 | 148354824082 |
| 19 | 712491943840 |
| 20 | 3430294543918 |
| 21 | 16552408346485 |
| 22 | 80031153498705 |
| 23 | 387658022884679 |
| 24 | 1880841554614987 |
| 25 | 9139197220529013 |
| 26 | 44469134400275800 |
| 27 | 216648203834175807 |
[1,2,6,22,84,349,1489,6522,29167,131937,604928, 2795191,13026035,61071104,287955729,1364135422, 6488835986,30978176466,148354824082,712491943840, 3430294543918,16552408346485,80031153498705, 387658022884679,1880841554614987,9139197220529013, 44469134400275800,216648203834175807] |