n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 22 |
4 | 140 |
5 | 992 |
6 | 7584 |
7 | 61420 |
8 | 520320 |
9 | 4570292 |
10 | 41354416 |
11 | 383609434 |
12 | 3634231140 |
13 | 35059333218 |
14 | 343580813492 |
15 | 3413862553800 |
16 | 34336784362232 |
17 | 349131316634164 |
18 | 3584622273967324 |
19 | 37128374058146138 |
20 | 387630493693010928 |
[1,1,4,22,140,992,7584,61420,520320,4570292, 41354416,383609434,3634231140,35059333218, 343580813492,3413862553800,34336784362232, 349131316634164,3584622273967324, 37128374058146138,387630493693010928] |