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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 16 |
| 4 | 0 |
| 5 | 164 |
| 6 | 1488 |
| 7 | 12756 |
| 8 | 62176 |
| 9 | 379376 |
| 10 | 2426224 |
| 11 | 13367704 |
| 12 | 72972656 |
| 13 | 402564940 |
| 14 | 2167170608 |
| 15 | 11412234916 |
| 16 | 59638462576 |
| 17 | 308861005448 |
| 18 | 1581575598752 |
| 19 | 8029891390392 |
| 20 | 40482609620976 |
| 21 | 202672272980456 |
| 22 | 1008192626002544 |
| 23 | 4987067296004984 |
| 24 | 24540946112970792 |
[0,0,16,0,164,1488,12756,62176,379376,2426224, 13367704,72972656,402564940,2167170608, 11412234916,59638462576,308861005448, 1581575598752,8029891390392,40482609620976, 202672272980456,1008192626002544,4987067296004984, 24540946112970792] |