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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 7 |
| 8 | 11 |
| 9 | 28 |
| 10 | 51 |
| 11 | 154 |
| 12 | 389 |
| 13 | 1556 |
| 14 | 4833 |
| 15 | 22477 |
| 16 | 80532 |
| 17 | 440512 |
| 18 | 1916580 |
| 19 | 13388593 |
| 20 | 73763989 |
| 21 | 632754664 |
| 22 | 4175659899 |
| 23 | 42606281476 |
| 24 | 336819337955 |
| 25 | 4181786155008 |
| 26 | 40981322633555 |
| 27 | 630857431556758 |
| 28 | 7576627032674784 |
[1,1,1,1,1,2,3,7,11,28,51,154,389,1556,4833,22477, 80532,440512,1916580,13388593,73763989,632754664, 4175659899,42606281476,336819337955,4181786155008, 40981322633555,630857431556758,7576627032674784] |