n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 1 |
4 | 4 |
5 | 8 |
6 | 38 |
7 | 206 |
8 | 1200 |
9 | 6824 |
10 | 50912 |
11 | 547552 |
12 | 4372912 |
13 | 50243280 |
14 | 557844400 |
15 | 6991479552 |
16 | 99545556480 |
17 | 1388702331776 |
18 | 20997495005568 |
19 | 347714276937216 |
20 | 5833018374594560 |
21 | 105073644198025984 |
[1,1,1,4,8,38,206,1200,6824,50912,547552,4372912, 50243280,557844400,6991479552,99545556480, 1388702331776,20997495005568,347714276937216, 5833018374594560,105073644198025984] |