n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 6 |
4 | 36 |
5 | 220 |
6 | 1410 |
7 | 9534 |
8 | 68040 |
9 | 511704 |
10 | 4046310 |
11 | 33560010 |
12 | 291244668 |
13 | 2638581972 |
14 | 24901833866 |
15 | 244333004790 |
16 | 2487900487440 |
17 | 26245651191600 |
18 | 286408960814862 |
19 | 3228529392965250 |
20 | 37544229610105220 |
21 | 449858650676764140 |
[0,0,1,6,36,220,1410,9534,68040,511704,4046310, 33560010,291244668,2638581972,24901833866, 244333004790,2487900487440,26245651191600, 286408960814862,3228529392965250, 37544229610105220,449858650676764140] |