n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 28 |
3 | 220 |
4 | 1816 |
5 | 15424 |
6 | 133456 |
7 | 1169872 |
8 | 10354528 |
9 | 92331904 |
10 | 828204928 |
11 | 7464652672 |
12 | 67547774464 |
13 | 613295870464 |
14 | 5584367987968 |
15 | 50974595472640 |
16 | 466307503244800 |
17 | 4273832891668480 |
18 | 39237007284226048 |
19 | 360768875975526400 |
20 | 3321625537178669056 |
21 | 30619908430235828224 |
22 | 282578914501599305728 |
[1,4,28,220,1816,15424,133456,1169872,10354528, 92331904,828204928,7464652672,67547774464, 613295870464,5584367987968,50974595472640, 466307503244800,4273832891668480, 39237007284226048,360768875975526400, 3321625537178669056,30619908430235828224, 282578914501599305728] |