n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 4 |
3 | 12 |
4 | 56 |
5 | 240 |
6 | 1324 |
7 | 7392 |
8 | 49136 |
9 | 337920 |
10 | 2652244 |
11 | 21660672 |
12 | 196658216 |
13 | 1859020800 |
14 | 19192151164 |
15 | 206057828352 |
16 | 2385488163296 |
17 | 28669154426880 |
18 | 367966308562084 |
19 | 4893320282898432 |
20 | 68978503204900376 |
21 | 1005520890400604160 |
22 | 15445185289163949004 |
23 | 244890632417194278912 |
[0,0,4,12,56,240,1324,7392,49136,337920,2652244, 21660672,196658216,1859020800,19192151164, 206057828352,2385488163296,28669154426880, 367966308562084,4893320282898432, 68978503204900376,1005520890400604160, 15445185289163949004,244890632417194278912] |