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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 2 |
| 8 | 4 |
| 9 | 8 |
| 10 | 15 |
| 11 | 30 |
| 12 | 60 |
| 13 | 119 |
| 14 | 236 |
| 15 | 468 |
| 16 | 928 |
| 17 | 1841 |
| 18 | 3652 |
| 19 | 7244 |
| 20 | 14369 |
| 21 | 28502 |
| 22 | 56536 |
| 23 | 112144 |
| 24 | 222447 |
| 25 | 441242 |
| 26 | 875240 |
| 27 | 1736111 |
| 28 | 3443720 |
| 29 | 6830904 |
| 30 | 13549664 |
| 31 | 26876881 |
| 32 | 53312520 |
| 33 | 105749800 |
| 34 | 209763489 |
| 35 | 416083258 |
| 36 | 825335612 |
| 37 | 1637121560 |
| 38 | 3247366239 |
[0,0,0,1,0,0,1,2,4,8,15,30,60,119,236,468,928, 1841,3652,7244,14369,28502,56536,112144,222447, 441242,875240,1736111,3443720,6830904,13549664, 26876881,53312520,105749800,209763489,416083258, 825335612,1637121560,3247366239] |