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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 6 |
| 7 | 17 |
| 8 | 41 |
| 9 | 94 |
| 10 | 215 |
| 11 | 470 |
| 12 | 1004 |
| 13 | 2126 |
| 14 | 4449 |
| 15 | 9278 |
| 16 | 19177 |
| 17 | 39388 |
| 18 | 80698 |
| 19 | 164808 |
| 20 | 335809 |
| 21 | 683117 |
| 22 | 1387415 |
| 23 | 2813664 |
| 24 | 5700228 |
| 25 | 11536241 |
| 26 | 23324624 |
| 27 | 47122764 |
| 28 | 95134678 |
| 29 | 191937316 |
| 30 | 387024829 |
| 31 | 780018815 |
| 32 | 1571331010 |
| 33 | 3164113363 |
[0,0,0,1,2,6,17,41,94,215,470,1004,2126,4449,9278, 19177,39388,80698,164808,335809,683117,1387415, 2813664,5700228,11536241,23324624,47122764, 95134678,191937316,387024829,780018815,1571331010, 3164113363] |