n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 1 |
4 | 4 |
5 | 8 |
6 | 38 |
7 | 206 |
8 | 1200 |
9 | 7244 |
10 | 55112 |
11 | 581908 |
12 | 5247184 |
13 | 55925292 |
14 | 639349432 |
15 | 8767780308 |
16 | 118799034792 |
17 | 1747194021920 |
18 | 27367319522424 |
19 | 460554745080200 |
20 | 8173026498677400 |
21 | 152080799760722664 |
[1,1,1,4,8,38,206,1200,7244,55112,581908,5247184, 55925292,639349432,8767780308,118799034792, 1747194021920,27367319522424,460554745080200, 8173026498677400,152080799760722664] |