n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 8 |
3 | 30 |
4 | 112 |
5 | 420 |
6 | 1584 |
7 | 6006 |
8 | 22880 |
9 | 87516 |
10 | 335920 |
11 | 1293292 |
12 | 4992288 |
13 | 19315400 |
14 | 74884320 |
15 | 290845350 |
16 | 1131445440 |
17 | 4407922860 |
18 | 17194993200 |
19 | 67156001220 |
20 | 262564816800 |
21 | 1027583214840 |
22 | 4025232800160 |
23 | 15780742227900 |
24 | 61915399071552 |
[0,2,8,30,112,420,1584,6006,22880,87516,335920, 1293292,4992288,19315400,74884320,290845350, 1131445440,4407922860,17194993200,67156001220, 262564816800,1027583214840,4025232800160, 15780742227900,61915399071552] |