n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 8 |
5 | 60 |
6 | 440 |
7 | 3290 |
8 | 25424 |
9 | 204120 |
10 | 1705680 |
11 | 14836470 |
12 | 134240040 |
13 | 1262060228 |
14 | 12313382536 |
15 | 124509169330 |
16 | 1303109358880 |
17 | 14098102762160 |
18 | 157473907149600 |
19 | 1813923418494126 |
20 | 21523529286435000 |
21 | 262809607270736540 |
[0,0,0,1,8,60,440,3290,25424,204120,1705680, 14836470,134240040,1262060228,12313382536, 124509169330,1303109358880,14098102762160, 157473907149600,1813923418494126, 21523529286435000,262809607270736540] |