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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 15 |
| 7 | 31 |
| 8 | 63 |
| 9 | 128 |
| 10 | 262 |
| 11 | 545 |
| 12 | 1161 |
| 13 | 2547 |
| 14 | 5767 |
| 15 | 13456 |
| 16 | 32202 |
| 17 | 78544 |
| 18 | 194016 |
| 19 | 482726 |
| 20 | 1204874 |
| 21 | 3008782 |
| 22 | 7505420 |
| 23 | 18689551 |
| 24 | 46454971 |
| 25 | 115296751 |
| 26 | 285886839 |
| 27 | 708673484 |
| 28 | 1757339598 |
| 29 | 4361894604 |
| 30 | 10841959912 |
[0,0,0,1,3,7,15,31,63,128,262,545,1161,2547,5767, 13456,32202,78544,194016,482726,1204874,3008782, 7505420,18689551,46454971,115296751,285886839, 708673484,1757339598,4361894604,10841959912] |