n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 24 |
4 | 176 |
5 | 1456 |
6 | 13056 |
7 | 124032 |
8 | 1230592 |
9 | 12629760 |
10 | 133186560 |
11 | 1436098560 |
12 | 15774990336 |
13 | 176028860416 |
14 | 1990947110912 |
15 | 22783499599872 |
16 | 263411369705472 |
17 | 3073132646563840 |
18 | 36143187370967040 |
19 | 428157758086840320 |
20 | 5105072641718353920 |
21 | 61228492804372561920 |
[1,1,4,24,176,1456,13056,124032,1230592,12629760, 133186560,1436098560,15774990336,176028860416, 1990947110912,22783499599872,263411369705472, 3073132646563840,36143187370967040, 428157758086840320,5105072641718353920, 61228492804372561920] |