The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2592 |
| 3 | 0 |
| 4 | 1121472 |
| 5 | 0 |
| 6 | 194986080 |
| 7 | 0 |
| 8 | 18300435840 |
| 9 | 0 |
| 10 | 1080041397408 |
| 11 | 0 |
| 12 | 44042615547456 |
| 13 | 0 |
| 14 | 1323529602867936 |
| 15 | 0 |
| 16 | 30721376739859200 |
| 17 | 0 |
| 18 | 570951082378155808 |
| 19 | 1236950581248 |
| 20 | 8740628929823039424 |
[1,0,2592,0,1121472,0,194986080,0,18300435840,0, 1080041397408,0,44042615547456,0,1323529602867936, 0,30721376739859200,0,570951082378155808, 1236950581248,8740628929823039424] |