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| n | a(n) |
|---|---|
| 0 | -1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 2 |
| 4 | 4 |
| 5 | 12 |
| 6 | 32 |
| 7 | 88 |
| 8 | 240 |
| 9 | 656 |
| 10 | 1792 |
| 11 | 4896 |
| 12 | 13376 |
| 13 | 36544 |
| 14 | 99840 |
| 15 | 272768 |
| 16 | 745216 |
| 17 | 2035968 |
| 18 | 5562368 |
| 19 | 15196672 |
| 20 | 41518080 |
| 21 | 113429504 |
| 22 | 309895168 |
| 23 | 846649344 |
| 24 | 2313089024 |
| 25 | 6319476736 |
| 26 | 17265131520 |
| 27 | 47169216512 |
| 28 | 128868696064 |
| 29 | 352075825152 |
| 30 | 961889042432 |
| 31 | 2627929735168 |
[-1,1,0,2,4,12,32,88,240,656,1792,4896,13376, 36544,99840,272768,745216,2035968,5562368, 15196672,41518080,113429504,309895168,846649344, 2313089024,6319476736,17265131520,47169216512, 128868696064,352075825152,961889042432, 2627929735168] |