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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 4 |
| 5 | 11 |
| 6 | 21 |
| 7 | 1 |
| 8 | 37 |
| 9 | 173 |
| 10 | 1648 |
| 11 | 3610 |
| 12 | 1 |
| 13 | 25125 |
| 14 | 139086 |
| 15 | 474576 |
| 16 | 284493 |
| 17 | 984021 |
| 18 | 6536394 |
| 19 | 24265740 |
| 20 | 18678381 |
| 21 | 96214041 |
| 22 | 277799337 |
| 23 | 1282283505 |
| 24 | 2077807083 |
| 25 | 1899874619 |
| 26 | 19252363864 |
| 27 | 44221482398 |
| 28 | 1967547359 |
| 29 | 29743945411 |
| 30 | 1265868629 |
[0,0,1,3,4,11,21,1,37,173,1648,3610,1,25125, 139086,474576,284493,984021,6536394,24265740, 18678381,96214041,277799337,1282283505,2077807083, 1899874619,19252363864,44221482398,1967547359, 29743945411,1265868629] |