The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 4 |
| 3 | 96 |
| 4 | 4368 |
| 5 | 318720 |
| 6 | 34102336 |
| 7 | 5030914560 |
| 8 | 978697675008 |
| 9 | 242750559363072 |
| 10 | 74771153253336064 |
| 11 | 28000532879379456000 |
| 12 | 12528400144123416219648 |
| 13 | 6600840125120447062671360 |
| 14 | 4044932243925079634651398144 |
| 15 | 2852467766044703580371025002496 |
| 16 | 2293626296595266305722457178308608 |
[1,0,4,96,4368,318720,34102336,5030914560, 978697675008,242750559363072,74771153253336064, 28000532879379456000,12528400144123416219648, 6600840125120447062671360, 4044932243925079634651398144, 2852467766044703580371025002496, 2293626296595266305722457178308608] |