n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 4 |
3 | 6 |
4 | 64 |
5 | 300 |
6 | 2568 |
7 | 20160 |
8 | 193856 |
9 | 1989792 |
10 | 22687200 |
11 | 279956160 |
12 | 3737966208 |
13 | 53589444480 |
14 | 821522026752 |
15 | 13407498599040 |
16 | 232106716968960 |
17 | 4248256958023680 |
18 | 81968803604600832 |
19 | 1662870215019018240 |
20 | 35384007384670648320 |
21 | 788053048823608565760 |
[1,0,4,6,64,300,2568,20160,193856,1989792, 22687200,279956160,3737966208,53589444480, 821522026752,13407498599040,232106716968960, 4248256958023680,81968803604600832, 1662870215019018240,35384007384670648320, 788053048823608565760] |