n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 6 |
3 | 18 |
4 | 64 |
5 | 220 |
6 | 888 |
7 | 3192 |
8 | 15104 |
9 | 48096 |
10 | 338400 |
11 | 285120 |
12 | 13728768 |
13 | -75484032 |
14 | 1327431168 |
15 | -15621137280 |
16 | 232048220160 |
17 | -3468200017920 |
18 | 56208508250112 |
19 | -959557688285184 |
20 | 17344153658234880 |
21 | -330228975428997120 |
22 | 6611419866845122560 |
23 | -138844103855232061440 |
[1,2,6,18,64,220,888,3192,15104,48096,338400, 285120,13728768,-75484032,1327431168,-15621137280, 232048220160,-3468200017920,56208508250112, -959557688285184,17344153658234880, -330228975428997120,6611419866845122560, -138844103855232061440] |