n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 0 |
4 | 12 |
5 | 60 |
6 | 570 |
7 | 8190 |
8 | 134456 |
9 | 2408616 |
10 | 49307670 |
11 | 1159112130 |
12 | 30619757652 |
13 | 891045909468 |
14 | 28244653953698 |
15 | 969331283419590 |
16 | 35858099428919280 |
17 | 1423688804991442896 |
18 | 60402176709135347502 |
19 | 2726896792761748601226 |
20 | 130498364319404393167820 |
[0,0,1,0,12,60,570,8190,134456,2408616,49307670, 1159112130,30619757652,891045909468, 28244653953698,969331283419590,35858099428919280, 1423688804991442896,60402176709135347502, 2726896792761748601226,130498364319404393167820] |