n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 2 |
4 | 15 |
5 | 84 |
6 | 420 |
7 | 1980 |
8 | 9009 |
9 | 40040 |
10 | 175032 |
11 | 755820 |
12 | 3233230 |
13 | 13728792 |
14 | 57946200 |
15 | 243374040 |
16 | 1017958725 |
17 | 4242920400 |
18 | 17631691440 |
19 | 73078721100 |
20 | 302202005490 |
21 | 1247182879800 |
22 | 5137916074200 |
23 | 21132472200840 |
24 | 86794082253450 |
25 | 356013544661424 |
26 | 1458583920435600 |
27 | 5969389748449400 |
[0,0,0,2,15,84,420,1980,9009,40040,175032,755820, 3233230,13728792,57946200,243374040,1017958725, 4242920400,17631691440,73078721100,302202005490, 1247182879800,5137916074200,21132472200840, 86794082253450,356013544661424,1458583920435600, 5969389748449400] |