n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 9 |
4 | 44 |
5 | 270 |
6 | 2064 |
7 | 17682 |
8 | 171296 |
9 | 1867968 |
10 | 22470840 |
11 | 294493320 |
12 | 4195969392 |
13 | 64416698112 |
14 | 1059685905264 |
15 | 18609306423120 |
16 | 347179119075840 |
17 | 6855335163907200 |
18 | 142889687354283264 |
19 | 3133647091691585280 |
20 | 72124075333003155840 |
21 | 1738384773846440146560 |
[1,1,2,9,44,270,2064,17682,171296,1867968, 22470840,294493320,4195969392,64416698112, 1059685905264,18609306423120,347179119075840, 6855335163907200,142889687354283264, 3133647091691585280,72124075333003155840, 1738384773846440146560] |