n | a(n) |
---|---|
2 | 1 |
3 | 3 |
4 | 9 |
5 | 30 |
6 | 102 |
7 | 360 |
8 | 1290 |
9 | 4704 |
10 | 17334 |
11 | 64512 |
12 | 241836 |
13 | 912384 |
14 | 3459876 |
15 | 13178988 |
16 | 50389236 |
17 | 193295652 |
18 | 743610528 |
19 | 2867892588 |
20 | 11085281328 |
21 | 42933166380 |
22 | 166575534264 |
23 | 647329281456 |
24 | 2519234973996 |
25 | 9817121868084 |
[1,3,9,30,102,360,1290,4704,17334,64512,241836, 912384,3459876,13178988,50389236,193295652, 743610528,2867892588,11085281328,42933166380, 166575534264,647329281456,2519234973996, 9817121868084] |