n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 2 |
3 | 6 |
4 | 54 |
5 | 460 |
6 | 3890 |
7 | 42364 |
8 | 512806 |
9 | 6698724 |
10 | 98496252 |
11 | 1585046584 |
12 | 27568171818 |
13 | 520043947020 |
14 | 10550553510016 |
15 | 228796551051436 |
16 | 5291441028244966 |
17 | 129967582592816500 |
18 | 3377869204044947060 |
19 | 92652519380506887784 |
20 | 2674716530794339146244 |
[0,0,2,6,54,460,3890,42364,512806,6698724, 98496252,1585046584,27568171818,520043947020, 10550553510016,228796551051436,5291441028244966, 129967582592816500,3377869204044947060, 92652519380506887784,2674716530794339146244] |