n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 6 |
4 | 36 |
5 | 240 |
6 | 1800 |
7 | 15120 |
8 | 141120 |
9 | 1693440 |
10 | 21772800 |
11 | 299376000 |
12 | 4390848000 |
13 | 68497228800 |
14 | 1133317785600 |
15 | 19833061248000 |
16 | 396661224960000 |
17 | 8299373322240000 |
18 | 181400588328960000 |
19 | 4135933413900288000 |
20 | 98228418580131840000 |
21 | 2426819753156198400000 |
[1,1,2,6,36,240,1800,15120,141120,1693440, 21772800,299376000,4390848000,68497228800, 1133317785600,19833061248000,396661224960000, 8299373322240000,181400588328960000, 4135933413900288000,98228418580131840000, 2426819753156198400000] |