n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 2 |
4 | 9 |
5 | 30 |
6 | 88 |
7 | 240 |
8 | 624 |
9 | 1568 |
10 | 3840 |
11 | 9216 |
12 | 21760 |
13 | 50688 |
14 | 116736 |
15 | 266240 |
16 | 602112 |
17 | 1351680 |
18 | 3014656 |
19 | 6684672 |
20 | 14745600 |
21 | 32374784 |
22 | 70778880 |
23 | 154140672 |
24 | 334495744 |
25 | 723517440 |
26 | 1560281088 |
27 | 3355443200 |
28 | 7197425664 |
29 | 15401484288 |
30 | 32883343360 |
[0,0,0,2,9,30,88,240,624,1568,3840,9216,21760, 50688,116736,266240,602112,1351680,3014656, 6684672,14745600,32374784,70778880,154140672, 334495744,723517440,1560281088,3355443200, 7197425664,15401484288,32883343360] |