n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 22 |
4 | 136 |
5 | 984 |
6 | 8016 |
7 | 73392 |
8 | 742464 |
9 | 8254080 |
10 | 99838080 |
11 | 1307301120 |
12 | 18407831040 |
13 | 277570298880 |
14 | 4460506444800 |
15 | 76131788544000 |
16 | 1375048700928000 |
17 | 26208041287680000 |
18 | 525597067634688000 |
19 | 11065538390925312000 |
[1,4,22,136,984,8016,73392,742464,8254080, 99838080,1307301120,18407831040,277570298880, 4460506444800,76131788544000,1375048700928000, 26208041287680000,525597067634688000, 11065538390925312000] |