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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 39 |
| 5 | 149 |
| 6 | 621 |
| 7 | 2608 |
| 8 | 11362 |
| 9 | 50005 |
| 10 | 224087 |
| 11 | 1013844 |
| 12 | 4634939 |
| 13 | 21348758 |
| 14 | 99021584 |
| 15 | 461872495 |
| 16 | 2165291885 |
| 17 | 10194743118 |
| 18 | 48184538956 |
| 19 | 228506836782 |
| 20 | 1086931778012 |
| 21 | 5184096470608 |
| 22 | 24785574274311 |
| 23 | 118761815637600 |
| 24 | 570191410379617 |
| 25 | 2742543994332775 |
| 26 | 13213240012589938 |
| 27 | 63757133657178463 |
[1,1,3,10,39,149,621,2608,11362,50005,224087, 1013844,4634939,21348758,99021584,461872495, 2165291885,10194743118,48184538956,228506836782, 1086931778012,5184096470608,24785574274311, 118761815637600,570191410379617,2742543994332775, 13213240012589938,63757133657178463] |