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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 15 |
| 7 | 27 |
| 8 | 76 |
| 9 | 196 |
| 10 | 548 |
| 11 | 1388 |
| 12 | 3621 |
| 13 | 9894 |
| 14 | 27553 |
| 15 | 75346 |
| 16 | 205634 |
| 17 | 563729 |
| 18 | 1565409 |
| 19 | 4370226 |
| 20 | 12191929 |
| 21 | 33980329 |
| 22 | 94874987 |
| 23 | 265668404 |
| 24 | 745652478 |
| 25 | 2095025688 |
| 26 | 5889310438 |
| 27 | 16565399257 |
| 28 | 46633521554 |
| 29 | 131388795335 |
| 30 | 370434641340 |
| 31 | 1044917168292 |
[1,0,1,1,2,5,15,27,76,196,548,1388,3621,9894, 27553,75346,205634,563729,1565409,4370226, 12191929,33980329,94874987,265668404,745652478, 2095025688,5889310438,16565399257,46633521554, 131388795335,370434641340,1044917168292] |