n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 18 |
3 | 132 |
4 | 680 |
5 | 2880 |
6 | 10752 |
7 | 36736 |
8 | 117504 |
9 | 357120 |
10 | 1041920 |
11 | 2939904 |
12 | 8067072 |
13 | 21618688 |
14 | 56770560 |
15 | 146472960 |
16 | 372113408 |
17 | 932511744 |
18 | 2308571136 |
19 | 5653135360 |
20 | 13707509760 |
21 | 32942063616 |
22 | 78525759488 |
23 | 185799278592 |
24 | 436627046400 |
[0,1,18,132,680,2880,10752,36736,117504,357120, 1041920,2939904,8067072,21618688,56770560, 146472960,372113408,932511744,2308571136, 5653135360,13707509760,32942063616,78525759488, 185799278592,436627046400] |