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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 7 |
| 5 | 18 |
| 6 | 51 |
| 7 | 147 |
| 8 | 431 |
| 9 | 1295 |
| 10 | 3954 |
| 11 | 12219 |
| 12 | 38174 |
| 13 | 120373 |
| 14 | 382559 |
| 15 | 1224173 |
| 16 | 3940964 |
| 17 | 12754732 |
| 18 | 41476011 |
| 19 | 135446194 |
| 20 | 444016332 |
| 21 | 1460619970 |
| 22 | 4819995330 |
| 23 | 15951789030 |
| 24 | 52932499724 |
| 25 | 176073789065 |
| 26 | 587010353666 |
| 27 | 1961118581900 |
| 28 | 6564548926877 |
| 29 | 22013613082514 |
| 30 | 73945428978360 |
| 31 | 248781470115309 |
[1,1,1,3,7,18,51,147,431,1295,3954,12219,38174, 120373,382559,1224173,3940964,12754732,41476011, 135446194,444016332,1460619970,4819995330, 15951789030,52932499724,176073789065,587010353666, 1961118581900,6564548926877,22013613082514, 73945428978360,248781470115309] |