n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 40 |
3 | 640 |
4 | 14080 |
5 | 394240 |
6 | 13404160 |
7 | 536166400 |
8 | 24663654400 |
9 | 1282510028800 |
10 | 74385581670400 |
11 | 4760677226905600 |
12 | 333247405883392000 |
13 | 25326802847137792000 |
14 | 2076797833465298944000 |
15 | 182758209344946307072000 |
16 | 17179271678424952864768000 |
17 | 1717927167842495286476800000 |
[1,4,40,640,14080,394240,13404160,536166400, 24663654400,1282510028800,74385581670400, 4760677226905600,333247405883392000, 25326802847137792000,2076797833465298944000, 182758209344946307072000, 17179271678424952864768000, 1717927167842495286476800000] |