n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 12 |
3 | 64 |
4 | 336 |
5 | 1760 |
6 | 9216 |
7 | 48256 |
8 | 252672 |
9 | 1323008 |
10 | 6927360 |
11 | 36272128 |
12 | 189923328 |
13 | 994451456 |
14 | 5207015424 |
15 | 27264286720 |
16 | 142757658624 |
17 | 747488804864 |
18 | 3913902194688 |
19 | 20493457948672 |
20 | 107305138913280 |
21 | 561857001684992 |
[0,2,12,64,336,1760,9216,48256,252672,1323008, 6927360,36272128,189923328,994451456,5207015424, 27264286720,142757658624,747488804864, 3913902194688,20493457948672,107305138913280, 561857001684992] |