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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 7 |
| 6 | 9 |
| 7 | 37 |
| 8 | 44 |
| 9 | 122 |
| 10 | 360 |
| 11 | 837 |
| 12 | 1955 |
| 13 | 11063 |
| 14 | 21562 |
| 15 | 102402 |
| 16 | 455597 |
| 17 | 1800255 |
| 18 | 6701316 |
| 19 | 61868659 |
| 20 | 193623470 |
| 21 | 1467251281 |
| 22 | 10855933316 |
| 23 | 68253791333 |
| 24 | 417351118269 |
| 25 | 6197640479557 |
| 26 | 31389717866283 |
| 27 | 387573069042758 |
[1,2,2,3,4,7,9,37,44,122,360,837,1955,11063,21562, 102402,455597,1800255,6701316,61868659,193623470, 1467251281,10855933316,68253791333,417351118269, 6197640479557,31389717866283,387573069042758] |