n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 19 |
3 | 95 |
4 | 475 |
5 | 2376 |
6 | 11881 |
7 | 59406 |
8 | 297029 |
9 | 1485144 |
10 | 7425719 |
11 | 37128595 |
12 | 185642975 |
13 | 928214876 |
14 | 4641074381 |
15 | 23205371904 |
16 | 116026859520 |
17 | 580134297600 |
18 | 2900671488000 |
19 | 14503357440000 |
20 | 72516787200000 |
21 | 362583936000000 |
[1,4,19,95,475,2376,11881,59406,297029,1485144, 7425719,37128595,185642975,928214876,4641074381, 23205371904,116026859520,580134297600, 2900671488000,14503357440000,72516787200000, 362583936000000] |