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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 18 |
| 6 | 40 |
| 7 | 88 |
| 8 | 192 |
| 9 | 400 |
| 10 | 832 |
| 11 | 1728 |
| 12 | 3584 |
| 13 | 7424 |
| 14 | 15360 |
| 15 | 31744 |
| 16 | 65536 |
| 17 | 133120 |
| 18 | 270336 |
| 19 | 548864 |
| 20 | 1114112 |
| 21 | 2260992 |
| 22 | 4587520 |
| 23 | 9306112 |
| 24 | 18874368 |
| 25 | 38273024 |
| 26 | 77594624 |
| 27 | 157286400 |
| 28 | 318767104 |
| 29 | 645922816 |
| 30 | 1308622848 |
| 31 | 2650800128 |
[0,1,3,8,18,40,88,192,400,832,1728,3584,7424, 15360,31744,65536,133120,270336,548864,1114112, 2260992,4587520,9306112,18874368,38273024, 77594624,157286400,318767104,645922816,1308622848, 2650800128] |