n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 18 |
4 | 144 |
5 | 900 |
6 | 16200 |
7 | 132300 |
8 | 2116800 |
9 | 28576800 |
10 | 714420000 |
11 | 8644482000 |
12 | 311201352000 |
13 | 4382752374000 |
14 | 143169910884000 |
15 | 4026653743612500 |
16 | 128852919795600000 |
17 | 2327405863808025000 |
18 | 125679916645633350000 |
[1,4,18,144,900,16200,132300,2116800,28576800, 714420000,8644482000,311201352000,4382752374000, 143169910884000,4026653743612500, 128852919795600000,2327405863808025000, 125679916645633350000] |