n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 0 |
3 | 0 |
4 | 8 |
5 | 20 |
6 | 96 |
7 | 656 |
8 | 5568 |
9 | 48912 |
10 | 494080 |
11 | 5383552 |
12 | 65097600 |
13 | 840566080 |
14 | 11833898496 |
15 | 176621049600 |
16 | 2838024476672 |
17 | 48060623405312 |
18 | 868000333234176 |
19 | 16441638519762944 |
20 | 329723762151352320 |
21 | 6907027877807330304 |
[0,1,0,0,8,20,96,656,5568,48912,494080,5383552, 65097600,840566080,11833898496,176621049600, 2838024476672,48060623405312,868000333234176, 16441638519762944,329723762151352320, 6907027877807330304] |