n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 4 |
3 | 44 |
4 | 360 |
5 | 2680 |
6 | 19244 |
7 | 136164 |
8 | 957520 |
9 | 6715760 |
10 | 47049684 |
11 | 329465884 |
12 | 2306615480 |
13 | 16147371240 |
14 | 113034787324 |
15 | 791253077204 |
16 | 5538800238240 |
17 | 38771687761120 |
18 | 271402072608164 |
19 | 1899815283098124 |
20 | 13298709306209800 |
[0,0,4,44,360,2680,19244,136164,957520,6715760, 47049684,329465884,2306615480,16147371240, 113034787324,791253077204,5538800238240, 38771687761120,271402072608164,1899815283098124, 13298709306209800] |