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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 1 |
| 2 | -1 |
| 3 | 6 |
| 4 | 16 |
| 5 | 20 |
| 6 | 35 |
| 7 | 79 |
| 8 | 156 |
| 9 | 288 |
| 10 | 552 |
| 11 | 1077 |
| 12 | 2079 |
| 13 | 3994 |
| 14 | 7696 |
| 15 | 14848 |
| 16 | 28623 |
| 17 | 55159 |
| 18 | 106320 |
| 19 | 204952 |
| 20 | 395060 |
| 21 | 761489 |
| 22 | 1467815 |
| 23 | 2829318 |
| 24 | 5453688 |
| 25 | 10512308 |
| 26 | 20263123 |
| 27 | 39058439 |
| 28 | 75287564 |
| 29 | 145121432 |
| 30 | 279730552 |
| 31 | 539197989 |
| 32 | 1039337543 |
| 33 | 2003387514 |
| 34 | 3861653592 |
| 35 | 7443576640 |
| 36 | 14347955295 |
[4,1,-1,6,16,20,35,79,156,288,552,1077,2079,3994, 7696,14848,28623,55159,106320,204952,395060, 761489,1467815,2829318,5453688,10512308,20263123, 39058439,75287564,145121432,279730552,539197989, 1039337543,2003387514,3861653592,7443576640, 14347955295] |