n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 12 |
4 | 84 |
5 | 680 |
6 | 6750 |
7 | 78372 |
8 | 1035608 |
9 | 15402816 |
10 | 254672730 |
11 | 4631221100 |
12 | 91872810612 |
13 | 1974481960464 |
14 | 45698618329910 |
15 | 1133221107064620 |
16 | 29974735063385520 |
17 | 842413032202481792 |
18 | 25067919890384214066 |
19 | 787394937539847359052 |
20 | 26034146454319615550540 |
[1,1,2,12,84,680,6750,78372,1035608,15402816, 254672730,4631221100,91872810612,1974481960464, 45698618329910,1133221107064620,29974735063385520, 842413032202481792,25067919890384214066, 787394937539847359052,26034146454319615550540] |