n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 20 |
6 | 80 |
7 | 336 |
8 | 1344 |
9 | 5440 |
10 | 21760 |
11 | 87296 |
12 | 349184 |
13 | 1397760 |
14 | 5591040 |
15 | 22368256 |
16 | 89473024 |
17 | 357908480 |
18 | 1431633920 |
19 | 5726601216 |
20 | 22906404864 |
21 | 91625881600 |
22 | 366503526400 |
23 | 1466015154176 |
24 | 5864060616704 |
25 | 23456246661120 |
26 | 93824986644480 |
27 | 375299963355136 |
28 | 1501199853420544 |
29 | 6004799480791040 |
[0,0,1,4,20,80,336,1344,5440,21760,87296,349184, 1397760,5591040,22368256,89473024,357908480, 1431633920,5726601216,22906404864,91625881600, 366503526400,1466015154176,5864060616704, 23456246661120,93824986644480,375299963355136, 1501199853420544,6004799480791040] |