The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 16 |
| 3 | 4128 |
| 4 | 1065008 |
| 5 | 274767936 |
| 6 | 70889062480 |
| 7 | 18289103351904 |
| 8 | 4718517775728752 |
| 9 | 1217359297034666112 |
| 10 | 314073980117168128144 |
| 11 | 81029869510932342395040 |
| 12 | 20905392259840427169792176 |
[0,16,4128,1065008,274767936,70889062480, 18289103351904,4718517775728752, 1217359297034666112,314073980117168128144, 81029869510932342395040, 20905392259840427169792176] |