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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 4 |
| 7 | 12 |
| 8 | 30 |
| 9 | 70 |
| 10 | 157 |
| 11 | 348 |
| 12 | 748 |
| 13 | 1603 |
| 14 | 3379 |
| 15 | 7076 |
| 16 | 14720 |
| 17 | 30472 |
| 18 | 62837 |
| 19 | 129141 |
| 20 | 264711 |
| 21 | 541301 |
| 22 | 1104733 |
| 23 | 2250778 |
| 24 | 4578841 |
| 25 | 9303111 |
| 26 | 18880287 |
| 27 | 38277715 |
| 28 | 77533844 |
| 29 | 156924293 |
| 30 | 317374503 |
| 31 | 641463198 |
| 32 | 1295724682 |
[0,0,0,0,1,4,12,30,70,157,348,748,1603,3379,7076, 14720,30472,62837,129141,264711,541301,1104733, 2250778,4578841,9303111,18880287,38277715, 77533844,156924293,317374503,641463198,1295724682] |