n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 8 |
5 | 40 |
6 | 240 |
7 | 1120 |
8 | 4480 |
9 | 17280 |
10 | 65280 |
11 | 253440 |
12 | 1015808 |
13 | 4126720 |
14 | 16773120 |
15 | 67624960 |
16 | 270499840 |
17 | 1077903360 |
18 | 4294901760 |
19 | 17146183680 |
20 | 68585259008 |
21 | 274608947200 |
22 | 1099510579200 |
23 | 4400191897600 |
24 | 17600767590400 |
25 | 70385915658240 |
26 | 281474959933440 |
[0,0,0,8,40,240,1120,4480,17280,65280,253440, 1015808,4126720,16773120,67624960,270499840, 1077903360,4294901760,17146183680,68585259008, 274608947200,1099510579200,4400191897600, 17600767590400,70385915658240,281474959933440] |