n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 28 |
4 | 280 |
5 | 3640 |
6 | 58240 |
7 | 1106560 |
8 | 24344320 |
9 | 608608000 |
10 | 17041024000 |
11 | 528271744000 |
12 | 17961239296000 |
13 | 664565853952000 |
14 | 26582634158080000 |
15 | 1143053268797440000 |
16 | 52580450364682240000 |
17 | 2576442067869429760000 |
18 | 133974987529210347520000 |
19 | 7368624314106569113600000 |
[1,1,4,28,280,3640,58240,1106560,24344320, 608608000,17041024000,528271744000,17961239296000, 664565853952000,26582634158080000, 1143053268797440000,52580450364682240000, 2576442067869429760000,133974987529210347520000, 7368624314106569113600000] |