| n | a(n) |
|---|---|
| 2 | 0 |
| 3 | 12 |
| 4 | 120 |
| 5 | 57120 |
| 6 | 93321840 |
| 7 | 10431955353116229600 |
| 8 | 8557304989566294213168677685339060480 |
| 9 | 102743047168201563425402150421568484707810385382513037790885688657488312400960 |
[0,12,120,57120,93321840,10431955353116229600, 8557304989566294213168677685339060480, 10274304716820156342540215042156848470781038538251\ 3037790885688657488312400960] |