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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 3 |
| 5 | 2 |
| 6 | 6 |
| 7 | 12 |
| 8 | 13 |
| 9 | 42 |
| 10 | 42 |
| 11 | 117 |
| 12 | 156 |
| 13 | 312 |
| 14 | 531 |
| 15 | 894 |
| 16 | 1641 |
| 17 | 2757 |
| 18 | 4866 |
| 19 | 8643 |
| 20 | 14525 |
| 21 | 26637 |
| 22 | 44292 |
| 23 | 80738 |
| 24 | 136563 |
| 25 | 243747 |
| 26 | 420347 |
| 27 | 739188 |
| 28 | 1286250 |
| 29 | 2252976 |
| 30 | 3921546 |
| 31 | 6879438 |
| 32 | 11951510 |
| 33 | 20993796 |
| 34 | 36461328 |
| 35 | 64002901 |
| 36 | 111314775 |
| 37 | 195060591 |
| 38 | 339831254 |
[0,0,1,0,3,2,6,12,13,42,42,117,156,312,531,894, 1641,2757,4866,8643,14525,26637,44292,80738, 136563,243747,420347,739188,1286250,2252976, 3921546,6879438,11951510,20993796,36461328, 64002901,111314775,195060591,339831254] |