n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 8 |
3 | 40 |
4 | 208 |
5 | 1088 |
6 | 5696 |
7 | 29824 |
8 | 156160 |
9 | 817664 |
10 | 4281344 |
11 | 22417408 |
12 | 117379072 |
13 | 614604800 |
14 | 3218112512 |
15 | 16850255872 |
16 | 88229085184 |
17 | 461973487616 |
18 | 2418924584960 |
19 | 12665653559296 |
20 | 66318223015936 |
21 | 347246723858432 |
22 | 1818207451086848 |
23 | 9520257811087360 |
[1,2,8,40,208,1088,5696,29824,156160,817664, 4281344,22417408,117379072,614604800,3218112512, 16850255872,88229085184,461973487616, 2418924584960,12665653559296,66318223015936, 347246723858432,1818207451086848,9520257811087360] |