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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 7 |
| 6 | 28 |
| 7 | 84 |
| 8 | 211 |
| 9 | 476 |
| 10 | 1029 |
| 11 | 2276 |
| 12 | 5384 |
| 13 | 13594 |
| 14 | 35371 |
| 15 | 91667 |
| 16 | 232681 |
| 17 | 577710 |
| 18 | 1413462 |
| 19 | 3442498 |
| 20 | 8414484 |
| 21 | 20717963 |
| 22 | 51346109 |
| 23 | 127678961 |
| 24 | 317496621 |
| 25 | 787941379 |
| 26 | 1950774874 |
| 27 | 4821609252 |
| 28 | 11910608942 |
| 29 | 29432604429 |
| 30 | 72787392898 |
| 31 | 180131835001 |
[1,0,0,0,1,7,28,84,211,476,1029,2276,5384,13594, 35371,91667,232681,577710,1413462,3442498,8414484, 20717963,51346109,127678961,317496621,787941379, 1950774874,4821609252,11910608942,29432604429, 72787392898,180131835001] |